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  • The HTG Guide to Using a Bluetooth Keyboard with Your Android Device

    - by Matt Klein
    Android devices aren’t usually associated with physical keyboards. But, since Google is now bundling their QuickOffice app with the newly-released Kit-Kat, it appears inevitable that at least some Android tablets (particularly 10-inch models) will take on more productivity roles. In recent years, physical keyboards have been rendered obsolete by swipe style input methods such as Swype and Google Keyboard. Physical keyboards tend to make phones thick and plump, and that won’t fly today when thin (and even flexible and curved) is in vogue. So, you’ll be hard-pressed to find smartphone manufacturers launching new models with physical keyboards, thus rendering sliders to a past chapter in mobile phone evolution. It makes sense to ditch the clunky keyboard phone in favor of a lighter, thinner model. You’re going to carry around in your pocket or purse all day, why have that extra bulk and weight? That said, there is sound logic behind pairing tablets with keyboards. Microsoft continues to plod forward with its Surface models, and while critics continue to lavish praise on the iPad, its functionality is obviously enhanced and extended when you add a physical keyboard. Apple even has an entire page devoted specifically to iPad-compatible keyboards. But an Android tablet and a keyboard? Does such a thing even exist? They do actually. There are docking keyboards and keyboard/case combinations, there’s the Asus Transformer family, Logitech markets a Windows 8 keyboard that speaks “Android”, and these are just to name a few. So we know that keyboard products that are designed to work with Android exist, but what about an everyday Bluetooth keyboard you might use with Windows or OS X? How-To Geek wanted look at how viable it is to use such a keyboard with Android. We conducted some research and examined some lists of Android keyboard shortcuts. Most of what we found was long outdated. Many of the shortcuts don’t even apply anymore, while others just didn’t work. Regardless, after a little experimentation and a dash of customization, it turns out using a keyboard with Android is kind of fun, and who knows, maybe it will catch on. Setting things up Setting up a Bluetooth keyboard with Android is very easy. First, you’ll need a Bluetooth keyboard and of course an Android device, preferably running version 4.1 (Jelly Bean) or higher. For our test, we paired a second-generation Google Nexus 7 running Android 4.3 with a Samsung Series 7 keyboard. In Android, enable Bluetooth if it isn’t already on. We’d like to note that if you don’t normally use Bluetooth accessories and peripherals with your Android device (or any device really), it’s best practice to leave Bluetooth off because, like GPS, it drains the device’s battery more quickly. To enable Bluetooth, simply go to “Settings” -> “Bluetooth” and tap the slider button to “On”. To set up the keyboard, make sure it is on and then tap “Bluetooth” in the Android settings. On the resulting screen, your Android device should automatically search for and hopefully find your keyboard. If you don’t get it right the first time, simply turn the keyboard on again and then tap “Search for Devices” to try again. If it still doesn’t work, make sure you have fresh batteries and the keyboard isn’t paired to another device. If it is, you will need to unpair it before it will work with your Android device (consult your keyboard manufacturer’s documentation or Google if you don’t know how to do this). When Android finds your keyboard, select it under “Available Devices” … … and you should be prompted to type in a code: If successful, you will see that device is now “Connected” and you’re ready to go. If you want to test things out, try pressing the “Windows” key (“Apple” or “Command”) + ESC, and you will be whisked to your Home screen. So, what can you do? Traditional Mac and Windows users know there’s usually a keyboard shortcut for just about everything (and if there isn’t, there’s all kinds of ways to remap keys to do a variety of commands, tasks, and functions). So where does Android fall in terms of baked-in keyboard commands? There answer to that is kind of enough, but not too much. There are definitely established combos you can use to get around, but they aren’t clear and there doesn’t appear to be any one authority on what they are. Still, there is enough keyboard functionality in Android to make it a viable option, if only for those times when you need to get something done (long e-mail or important document) and an on-screen keyboard simply won’t do. It’s important to remember that Android is, and likely always will be a touch-first interface. That said, it does make some concessions to physical keyboards. In other words, you can get around Android fairly well without having to lift your hands off the keys, but you will still have to tap the screen regularly, unless you add a mouse. For example, you can wake your device by tapping a key rather than pressing its power button. However, if your device is slide or pattern-locked, then you’ll have to use the touchscreen to unlock it – a password or PIN however, works seamlessly with a keyboard – other things like widgets and app controls and features, have to be tapped. You get the idea. Keyboard shortcuts and navigation As we said, baked-in keyboard shortcut combos aren’t necessarily abundant nor apparent. The one thing you can always do is search. Any time you want to Google something, start typing from the Home screen and the search screen will automatically open and begin displaying results. Other than that, here is what we were able to figure out: ESC = go back CTRL + ESC = menu CTRL + ALT + DEL = restart (no questions asked) ALT + SPACE = search page (say “OK Google” to voice search) ALT + TAB (ALT + SHIFT + TAB) = switch tasks Also, if you have designated volume function keys, those will probably work too. There’s also some dedicated app shortcuts like calculator, Gmail, and a few others: CMD + A = calculator CMD + C = contacts CMD + E = e-mail CMD + G = Gmail CMD + L = Calendar CMD + P = Play Music CMD + Y = YouTube Overall, it’s not a long comprehensive list and there’s no dedicated keyboard combos for the full array of Google’s products. Granted, it’s hard to imagine getting a lot of mileage out of a keyboard with Maps but with something like Keep, you could type out long, detailed lists on your tablet, and then view them on your smartphone when you go out shopping. You can also use the arrow keys to navigate your Home screen over shortcuts and open the app drawer. When something on the screen is selected, it will be highlighted in blue. Press “Enter” to open your selection. Additionally, if an app has its own set of shortcuts, e.g. Gmail has quite a few unique shortcuts to it, as does Chrome, some – though not many – will work in Android (not for YouTube though). Also, many “universal” shortcuts such as Copy (CTRL + C), Cut (CTRL + X), Paste (CTRL + V), and Select All (CTRL + A) work where needed – such as in instant messaging, e-mail, social media apps, etc. Creating custom application shortcuts What about custom shortcuts? When we were researching this article, we were under the impression that it was possible to assign keyboard combinations to specific apps, such as you could do on older Android versions such as Gingerbread. This no long seems to be the case and nowhere in “Settings” could we find a way to assign hotkey combos to any of our favorite, oft-used apps or functions. If you do want custom keyboard shortcuts, what can you do? Luckily, there’s an app on Google Play that allows you to, among other things, create custom app shortcuts. It is called External Keyboard Helper (EKH) and while there is a free demo version, the pay version is only a few bucks. We decided to give EKH a whirl and through a little experimentation and finally reading the developer’s how-to, we found we could map custom keyboard combos to just about anything. To do this, first open the application and you’ll see the main app screen. Don’t worry about choosing a custom layout or anything like that, you want to go straight to the “Advanced settings”: In the “Advanced settings” select “Application shortcuts” to continue: You can have up to 16 custom application shortcuts. We are going to create a custom shortcut to the Facebook app. We choose “A0”, and from the resulting list, Facebook. You can do this for any number of apps, services, and settings. As you can now see, the Facebook app has now been linked to application-zero (A0): Go back to the “Advanced settings” and choose “Customize keyboard mappings”: You will be prompted to create a custom keyboard layout so we choose “Custom 1”: When you choose to create a custom layout, you can do a great many more things with your keyboard. For example, many keyboards have predefined function (Fn) keys, which you can map to your tablet’s brightness controls, toggle WiFi on/off, and much more. A word of advice, the application automatically remaps certain keys when you create a custom layout. This might mess up some existing keyboard combos. If you simply want to add some functionality to your keyboard, you can go ahead and delete EKH’s default changes and start your custom layout from scratch. To create a new combo, select “Add new key mapping”: For our new shortcut, we are going to assign the Facebook app to open when we key in “ALT + F”. To do this, we press the “F” key while in the “Scancode” field and we see it returns a value of “33”. If we wanted to use a different key, we can press “Change” and scan another key’s numerical value. We now want to assign the “ALT” key to application “A0”, previously designated as the Facebook app. In the “AltGr” field, we enter “A0” and then “Save” our custom combo. And now we see our new application shortcut. Now, as long as we’re using our custom layout, every time we press “ALT + F”, the Facebook app will launch: External Keyboard Helper extends far beyond simple application shortcuts and if you are looking for deeper keyboard customization options, you should definitely check it out. Among other things, EKH also supports dozens of languages, allows you to quickly switch between layouts using a key or combo, add up to 16 custom text shortcuts, and much more! It can be had on Google Play for $2.53 for the full version, but you can try the demo version for free. More extensive documentation on how to use the app is also available. Android? Keyboard? Sure, why not? Unlike traditional desktop operating systems, you don’t need a physical keyboard and mouse to use a mobile operating system. You can buy an iPad or Nexus 10 or Galaxy Note, and never need another accessory or peripheral – they work as intended right out of the box. It’s even possible you can write the next great American novel on one these devices, though that might require a lot of practice and patience. That said, using a keyboard with Android is kind of fun. It’s not revelatory but it does elevate the experience. You don’t even need to add customizations (though they are nice) because there are enough existing keyboard shortcuts in Android to make it usable. Plus, when it comes to inputting text such as in an editor or terminal application, we fully advocate big, physical keyboards. Bottom line, if you’re looking for a way to enhance your Android tablet, give a keyboard a chance. Do you use your Android device for productivity? Is a physical keyboard an important part of your setup? Do you have any shortcuts that we missed? Sound off in the comments and let us know what you think.     

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  • Keyboard / keymap problems with Xubuntu 12.04 + NX nomachine

    - by bajafresh4life
    I'm running NX client on my Macbook Pro to connect to a Xubuntu 12.04 desktop at work. I have configured NX client to start up a console upon connection. I am able to connect to my remote linux machine and I get a simple xterm console. However, when I run xfce4-session, half my keys no longer work. For example, when I launch a terminal, I typing a, s, or d works, but if type w, e, r, or t, the cursor just blinks. If I ctrl-C out of xfce4-session, all the keys work fine in my xterm console. If I run xev, this is the output for when I hit a key that works: KeyRelease event, serial 34, synthetic NO, window 0x2e00001, root 0x373, subw 0x0, time 170160781, (-45,-21), root:(824,429), state 0x4, keycode 16 (keysym 0x63, c), same_screen YES, XLookupString gives 1 bytes: (03) "" XFilterEvent returns: False KeyRelease event, serial 34, synthetic NO, window 0x2e00001, root 0x373, subw 0x0, time 170160781, (-45,-21), root:(824,429), state 0x4, keycode 67 (keysym 0xffe3, Control_L), same_screen YES, XKeysymToKeycode returns keycode: 63 XLookupString gives 0 bytes: XFilterEvent returns: False but when I hit a key that doesn't work: FocusOut event, serial 34, synthetic NO, window 0x2e00001, mode NotifyGrab, detail NotifyAncestor FocusIn event, serial 34, synthetic NO, window 0x2e00001, mode NotifyUngrab, detail NotifyAncestor KeymapNotify event, serial 34, synthetic NO, window 0x0, keys: 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Any ideas on what I can do to troubleshoot this issue? Googling around offered a few suggestions (like playing with xmodmap) but nothing seemed to work. Also, one thing worth mentioning is that I do not have any keyboard issues when remoting into a different Ubuntu 10 box via NX.

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  • Acer aspire one d270 can not set brightness

    - by Marko
    I hope you can help me figure out how to set the brightness at my netbook. Following problem appears since I installed ubuntu 11.10 on my acer: I am not able to adjust the brightness by FN Keys nor manually at "systemsettings-display". After searching with google for a while, I found a way via the terminal to adjust it with the folloqing command: "sudo setpci -s 00:02.0 f4.b=7f" ( from 00-9f). That was a major breakthrough for me as I am still new to Linux OS. But still seeking a way to get the FN keys for brightness to work, I kept searching until I found "askubuntu.com". I read through various Questions by other acer users and tried there solutions, but unfortunately none worked out for me. From this thread: fn + arrow keys don't adjust actual brightness on an Acer Aspire 5740 "sudo gedit /etc/X11/xorg.conf". This command did not work because the file was not found. I also used nano instead of gedit, but the file was empty( I think it just created the file since it did not exist). These commands which i found gave me a boot loop and I had to repair ubuntu: sudo gedit /etc/default/grub Change the line GRUB_CMDLINE_LINUX="" into GRUB_CMDLINE_LINUX="acpi_osi=Linux" sudo update-grub From this post Screen Brightness not adjustable for Acer Aspire S3: I tried the solution from the last post, but it did not work either. Does anyone know what I could try? I would appreciate it, if someone could help me out with this. Thanks in advance Netbook specs: CPU: Intel Atom N2600 Memory: 2gb DDR3 Storage: 320 GB HD GPU: Intel GMA 3600

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  • How do I restore a backup of my keyring (containing ssh key passprases, nautilus remote filesystem passwords and wifi passwords)?

    - by con-f-use
    I changed the disk on my laptop and installed Ubuntu on the new disk. Old disk had 12.04 upgraded to 12.10 on it. Now I want to copy my old keyring with WiFi passwords, ftp passwords for nautilus and ssh key passphrases. I have the whole data from the old disk available (is now a USB disk and I did not delete the old data yet or do anything with it - I could still put it in the laptop and boot from it like nothing happend). The old methods of just copying ~/.gconf/... and ~/.gnome2/keyrings won't work. Did I miss something? 1. Edit: I figure one needs to copy files not located in the users home directory as well. I copied the whole old /home/confus (which is my home directory) to the fresh install to no effect. That whole copy is now reverted to the fresh install's home directory, so my /home/confus is as it was the after fresh install. 2. Edit: The folder /etc/NetworkManager/system-connections seems to be the place for WiFi passwords. Could be that /usr/share/keyrings is important as well for ssh keys - that's the only sensible thing that a search came up with: find /usr/ -name "*keyring* 3. Edit: Still no ssh and ftp passwords from the keyring. What I did: Convert old hard drive to usb drive Put new drive in the laptop and installed fresh version of 12.10 there Booted from old hdd via USB and copied its /etc/NetwrokManager/system-connections, ~/.gconf/ and ~/.gnome2/keyrings, ~/.ssh over to the new disk. Confirmed that all keys on the old install work Booted from new disk Result: No passphrase for ssh keys, no ftp passwords in keyring. At least the WiFi passwords are migrated.

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  • Spring to Java EE, Part Three - new tech article on otn/java

    - by Janice J. Heiss
    In a new article up on otn/java, Java EE expert David Heffelfinger continues his series exploring the relative strengths and weaknesses of Java EE and Spring. Here, he demonstrates how easy it is to develop the data layer of an application using Java EE, JPA, and the NetBeans IDE instead of the Spring Framework.In the first two parts of the series, he generated a complete Java EE application by using JavaServer Faces (JSF) 2.0, Enterprise JavaBeans (EJB) 3.1, and Java Persistence API (JPA) 2.0 from Spring’s Pet Clinic MySQL schema, thus showing how easy it is to develop an application whose functionality equaled that of the Spring sample application.In his new article, Heffelfinger tweaks the application to make it more user friendly.From the article:“The generated application displays primary keys on some of the pages, and these keys are surrogate primary keys—meaning that they have no business value and are used strictly as a unique identifier—so there is no reason why they should be visible to the user. In addition, we will modify some of the generated labels to make them more user-friendly.”He concludes the article with a summary:“The Java EE version of the application is not a straight port of the Spring version. For example, the Java EE version enables us to create, update, and delete veterinarians as well as veterinary specialties, whereas the Spring version of the application enables us only to view veterinarians and specialties. Additionally, the Spring version has a single page for managing/viewing owners, pets, and visits, whereas the Java EE version of the application has separate pages for each of these entities.The other thing we should keep in mind is that we didn’t actually write a lot of the code and markup for the Java EE version of the application, because the bulk of it was generated by the NetBeans wizard.” Have a look at the complete article here.

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  • "Walking" along a rotating surface in LimeJS

    - by Dave Lancea
    I'm trying to have a character walk along a plank (a long, thin rectangle) that works like a seesaw, being rotated around a central point by box2d physics (falling objects). I want the left and right arrow keys to move the player up and down the plank, regardless of it's slope, and I don't want to use real physics for the player movement. My idea for achieving this was to compute the coordinate based on the rotation of the plank and the current location "up" or "down" the board. My math is derived from here: http://math.stackexchange.com/questions/143932/calculate-point-given-x-y-angle-and-distance Here's the code I have so far: movement = 0; if(keys[37]){ // Left movement = -3; } if(keys[39]){ // Right movement = 3; } // this.plank is a LimeJS sprite. // getRotation() Should return an angle in degrees var rotation = this.plank.getRotation(); // this.current_plank_location is initialized as 0 this.current_plank_location += movement; var x_difference = this.current_plank_location * Math.cos(rotation); var y_difference = this.current_plank_location * Math.sin(rotation); this.setPosition(seesaw.PLANK_CENTER_X + x_difference, seesaw.PLANK_CENTER_Y + y_difference); This code causes the player to swing around in a circle when they are out of the center of the plank given a slight change in rotation of the plank. Any ideas on how I can get the player position to follow the board position?

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  • Cleaning Up After Chrome

    - by Mark Treadwell
    I find Google Chrome, which I have no interest in, is continually getting installed on machines in my house, mostly due to Adobe Shockwave bringing it along as an install package. (Family members are agreeing to the download, not realizing the Chrome is getting dropped as well.) My major issue after uninstalling Chrome is that you can no longer click on links in Outlook emails. There is a lot on the web about this, and Google has not been proactive at fixing their uninstaller. I have now added a registry file to my Win64 systems to reset the problem registry keys and clear the error. This registry file is pretty simple. It merely resets HKEY_CURRENT_USER\Software\Classes\.htm, HKEY_CURRENT_USER\Software\Classes\.html, and HKEY_CURRENT_USER\Software\Classes\.shtml back to their default values of "htmlfile". Chrome takes over the handling of these file extensions because its default install is to make itself the default web browser. The Chrome uninstalled fails to clear/reset them. In troubleshooting this, I looked in my registry based on the web info on the Chrome uninstall problem. Since my system had never had Chrome installed, my registry did not have the problem keys. To troubleshoot, I installed (ugh!) and uninstalled Chrome. Sure enough, Chrome left the expected debris with a value string of "ChromeHTML.PR2EPLWMBQZK3BY7Z2BFBMFERU" or something similar. Resetting these values fixed the problem. I see that Chrome leaves quite a bit of debris behind in the registry. I guess it is creating the keys then leaving them behind, even though their presence (with bad data) subsequently affects operations.

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  • this.BoundingBox.Intersects(Wall[0].BoundingBox) not working properly

    - by Pieter
    I seem to be having this problem a lot, I'm still learning XNA / C# and well, trying to make a classic paddle and ball game. The problem I run into (and after debugging have no answer) is that everytime I run my game and press either of the movement keys, the Paddle won't move. Debugging shows that it never gets to the movement part, but I can't understand why not? Here's my code: // This is the If statement for checking Left movement. if (keyboardState.IsKeyDown(Keys.Left) || keyboardState.IsKeyDown(Keys.A)) { if (!CheckCollision(walls[0])) { Location.X -= Velocity; } } //This is the CheckCollision(Wall wall) boolean public bool CheckCollision(Wall wall) { if (this.BoundingBox.Intersects(wall.BoundingBox)) { return true; } return false; } As far as I can tell there should be absolutely no problem with this, I initialize the bounding box in the constructor whenever a new instance of Walls and Paddle is created. this.BoundingBox = new Rectangle(0, 0, Sprite.Width, Sprite.Height); Any idea as to why this isn't working? I have previously succeeded with using the whole Location.X < Wall.Location.X + Wall.Texture.Width code... But to me that seems like too much coding if a simple boolean check could be done.

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  • Facing a character towards the mouse

    - by ratata
    I'm trying to port a simple 2d top down shooter game from C++(Allegro) to Java and i'm having problems with rotating my character. Here's the code i used in c++ if (keys[A]) RotateRight(player, degree); if (keys[D]) RotateLeft(player, degree); void RotateLeft(Player& player, float& degree) { degree += player.rotatingSpeed; if ( degree >= 360 ) degree = 0; } void RotateRight(Player& player, float& degree) { degree -= player.rotatingSpeed; if ( degree <= 0) degree = 360; } And this is what i have in render section: al_draw_rotated_bitmap(player.image, player.frameWidth / 2, player.frameHeight / 2, player.x, player.y, degree * 3.14159 / 180, 0); Instead of using A-D keys i want to use mouse this time. I've been searching since last night and came up to few sample codes however noone of them worked. For example this just made my character to circle around the map: int centerX = width / 2; int centerY = height / 2; double angle = Math.atan2(centerY - mouseY, centerX - mouseX) - Math.PI / 2; ((Graphics2D)g).rotate(angle, centerX, centerY); g.fillRect(...); // draw your rectangle Any help is much appreciated.

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  • 2 folders in Sys/Class/Backlight?

    - by zebrapie
    ISSUE: Backlight brightness does not change. More Detail: Brightness will not change, using both 'System Settings-Screen', or FN keys (Brightness bar shows and moves, but screen brightness does not change). Notcied a post in this thread (http://ubuntuforums.org/showthread.php?t=1866283) about having multiple folders in Sys-Class-Backlight... I HAVE TWO FOLDERS TOO! 'intel_backlight' and 'acpi_video0' Using the function keys, alters the value in the acpi_video0's 'Brightness' file - But doesn't actually alter the brightness of the screen. If I add 'backlight=vendor' in Grub, my function keys then edit the value in the 'Intel_Backlight brightness file. - But again doesnt actually change the brightness of the screen. Computer: Fujitsu Siemans Pi2515, Intel Integrated Graphics, No hdd partition. Already Tried: -Editing grub to contain: acpi_osi=Linux acpi_backlight=vendor -http://ubuntuguide.net/change-screen-brightness-with-fn-key-in-ubuntu-11-0410-10 -sudo apt-get install acpi -$ sudo setpci -s 00:02.0 F4.B=20 -Brightness does not adjust in fallback mode either. -Reinstalling OS, Using Linux Mint (Same problem). -Upgrading and downgrading BIOS. Many thanks for reading, I understand this problem may need a bit of a Linux pro to sort. If anyones up for the challenge i'll spend any amount of time being walked through this, posting results. Don't want to give up here!

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  • Make a basic running sprite effect

    - by PhaDaPhunk
    I'm building my very first game with XNA and i'm trying to get my sprite to run. Everything is working fine for the first sprite. E.g : if I go right(D) my sprite is looking right , if I go left(A) my sprite is looking left and if I don't touch anything my sprite is the default one. Now what I want to do is if the sprite goes Right, i want to alternatively change sprites (left leg, right leg, left leg etc..) xCurrent is the current sprite drawn xRunRight is the first running Sprite and xRunRight1 is the one that have to exchange with xRunRight while running right. This is what I have now : protected override void Update(GameTime gameTime) { float timer = 0f; float interval = 50f; bool frame1 = false ; bool frame2 = false; bool running = false; KeyboardState FaKeyboard = Keyboard.GetState(); // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); if ((FaKeyboard.IsKeyUp(Keys.A)) || (FaKeyboard.IsKeyUp(Keys.D))) { xCurrent = xDefault; } if (FaKeyboard.IsKeyDown(Keys.D)) { timer += (float)gameTime.ElapsedGameTime.TotalMilliseconds; if (timer > interval) { if (frame1) { xCurrent = xRunRight; frame1 = false; } else { xCurrent = xRunRight1; frame1 = true; } } xPosition += xDeplacement; } Any ideas...? I've been stuck on this for a while.. Thanks in advance and let me know if you need any other part from the code.

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  • C# - How to override GetHashCode with Lists in object

    - by Christian
    Hi, I am trying to create a "KeySet" to modify UIElement behaviour. The idea is to create a special function if, eg. the user clicks on an element while holding a. Or ctrl+a. My approach so far, first lets create a container for all possible modifiers. If I would simply allow a single key, it would be no problem. I could use a simple Dictionary, with Dictionary<Keys, Action> _specialActionList If the dictionary is empty, use the default action. If there are entries, check what action to use depending on current pressed keys And if I wasn't greedy, that would be it... Now of course, I want more. I want to allow multiple keys or modifiers. So I created a wrapper class, wich can be used as Key to my dictionary. There is an obvious problem when using a more complex class. Currently two different instances would create two different key, and thereby he would never find my function (see code to understand, really obvious) Now I checked this post: http://stackoverflow.com/questions/638761/c-gethashcode-override-of-object-containing-generic-array which helped a little. But my question is, is my basic design for the class ok. Should I use a hashset to store the modifier and normal keyboardkeys (instead of Lists). And If so, how would the GetHashCode function look like? I know, its a lot of code to write (boring hash functions), some tips would be sufficient to get me started. Will post tryouts here... And here comes the code so far, the Test obviously fails... public class KeyModifierSet { private readonly List<Key> _keys = new List<Key>(); private readonly List<ModifierKeys> _modifierKeys = new List<ModifierKeys>(); private static readonly Dictionary<KeyModifierSet, Action> _testDict = new Dictionary<KeyModifierSet, Action>(); public static void Test() { _testDict.Add(new KeyModifierSet(Key.A), () => Debug.WriteLine("nothing")); if (!_testDict.ContainsKey(new KeyModifierSet(Key.A))) throw new Exception("Not done yet, help :-)"); } public KeyModifierSet(IEnumerable<Key> keys, IEnumerable<ModifierKeys> modifierKeys) { foreach (var key in keys) _keys.Add(key); foreach (var key in modifierKeys) _modifierKeys.Add(key); } public KeyModifierSet(Key key, ModifierKeys modifierKey) { _keys.Add(key); _modifierKeys.Add(modifierKey); } public KeyModifierSet(Key key) { _keys.Add(key); } }

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  • Looping class, for template engine kind of thing

    - by tarnfeld
    Hey, I am updating my class Nesty so it's infinite but I'm having a little trouble.... Here is the class: <?php Class Nesty { // Class Variables private $text; private $data = array(); private $loops = 0; private $maxLoops = 0; public function __construct($text,$data = array(),$maxLoops = 5) { // Set the class vars $this->text = $text; $this->data = $data; $this->maxLoops = $maxLoops; } // Loop funtion private function loopThrough($data) { if( ($this->loops +1) > $this->maxLoops ) { die("ERROR: Too many loops!"); } else { $keys = array_keys($data); for($x = 0; $x < count($keys); $x++) { if(is_array($data[$keys[$x]])) { $this->loopThrough($data[$keys[$x]]); } else { return $data[$keys[$x]]; } } } } // Templater method public function template() { echo $this->loopThrough($this->data); } } ?> Here is the code you would use to create an instance of the class: <?php // The nested array $data = array( "person" => array( "name" => "Tom Arnfeld", "age" => 15 ), "product" => array ( "name" => "Cakes", "price" => array ( "single" => 59, "double" => 99 ) ), "other" => "string" ); // Retreive the template text $file = "TestData.tpl"; $fp = fopen($file,"r"); $text = fread($fp,filesize($file)); // Create the Nesty object require_once('Nesty.php'); $nesty = new Nesty($text,$data); // Save the newly templated text to a variable $message $message = $nesty->template(); // Print out $message on the page echo("<pre>".$message."</pre>"); ?> Any ideas?

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  • Toorcon 15 (2013)

    - by danx
    The Toorcon gang (senior staff): h1kari (founder), nfiltr8, and Geo Introduction to Toorcon 15 (2013) A Tale of One Software Bypass of MS Windows 8 Secure Boot Breaching SSL, One Byte at a Time Running at 99%: Surviving an Application DoS Security Response in the Age of Mass Customized Attacks x86 Rewriting: Defeating RoP and other Shinanighans Clowntown Express: interesting bugs and running a bug bounty program Active Fingerprinting of Encrypted VPNs Making Attacks Go Backwards Mask Your Checksums—The Gorry Details Adventures with weird machines thirty years after "Reflections on Trusting Trust" Introduction to Toorcon 15 (2013) Toorcon 15 is the 15th annual security conference held in San Diego. I've attended about a third of them and blogged about previous conferences I attended here starting in 2003. As always, I've only summarized the talks I attended and interested me enough to write about them. Be aware that I may have misrepresented the speaker's remarks and that they are not my remarks or opinion, or those of my employer, so don't quote me or them. Those seeking further details may contact the speakers directly or use The Google. For some talks, I have a URL for further information. A Tale of One Software Bypass of MS Windows 8 Secure Boot Andrew Furtak and Oleksandr Bazhaniuk Yuri Bulygin, Oleksandr ("Alex") Bazhaniuk, and (not present) Andrew Furtak Yuri and Alex talked about UEFI and Bootkits and bypassing MS Windows 8 Secure Boot, with vendor recommendations. They previously gave this talk at the BlackHat 2013 conference. MS Windows 8 Secure Boot Overview UEFI (Unified Extensible Firmware Interface) is interface between hardware and OS. UEFI is processor and architecture independent. Malware can replace bootloader (bootx64.efi, bootmgfw.efi). Once replaced can modify kernel. Trivial to replace bootloader. Today many legacy bootkits—UEFI replaces them most of them. MS Windows 8 Secure Boot verifies everything you load, either through signatures or hashes. UEFI firmware relies on secure update (with signed update). You would think Secure Boot would rely on ROM (such as used for phones0, but you can't do that for PCs—PCs use writable memory with signatures DXE core verifies the UEFI boat loader(s) OS Loader (winload.efi, winresume.efi) verifies the OS kernel A chain of trust is established with a root key (Platform Key, PK), which is a cert belonging to the platform vendor. Key Exchange Keys (KEKs) verify an "authorized" database (db), and "forbidden" database (dbx). X.509 certs with SHA-1/SHA-256 hashes. Keys are stored in non-volatile (NV) flash-based NVRAM. Boot Services (BS) allow adding/deleting keys (can't be accessed once OS starts—which uses Run-Time (RT)). Root cert uses RSA-2048 public keys and PKCS#7 format signatures. SecureBoot — enable disable image signature checks SetupMode — update keys, self-signed keys, and secure boot variables CustomMode — allows updating keys Secure Boot policy settings are: always execute, never execute, allow execute on security violation, defer execute on security violation, deny execute on security violation, query user on security violation Attacking MS Windows 8 Secure Boot Secure Boot does NOT protect from physical access. Can disable from console. Each BIOS vendor implements Secure Boot differently. There are several platform and BIOS vendors. It becomes a "zoo" of implementations—which can be taken advantage of. Secure Boot is secure only when all vendors implement it correctly. Allow only UEFI firmware signed updates protect UEFI firmware from direct modification in flash memory protect FW update components program SPI controller securely protect secure boot policy settings in nvram protect runtime api disable compatibility support module which allows unsigned legacy Can corrupt the Platform Key (PK) EFI root certificate variable in SPI flash. If PK is not found, FW enters setup mode wich secure boot turned off. Can also exploit TPM in a similar manner. One is not supposed to be able to directly modify the PK in SPI flash from the OS though. But they found a bug that they can exploit from User Mode (undisclosed) and demoed the exploit. It loaded and ran their own bootkit. The exploit requires a reboot. Multiple vendors are vulnerable. They will disclose this exploit to vendors in the future. Recommendations: allow only signed updates protect UEFI fw in ROM protect EFI variable store in ROM Breaching SSL, One Byte at a Time Yoel Gluck and Angelo Prado Angelo Prado and Yoel Gluck, Salesforce.com CRIME is software that performs a "compression oracle attack." This is possible because the SSL protocol doesn't hide length, and because SSL compresses the header. CRIME requests with every possible character and measures the ciphertext length. Look for the plaintext which compresses the most and looks for the cookie one byte-at-a-time. SSL Compression uses LZ77 to reduce redundancy. Huffman coding replaces common byte sequences with shorter codes. US CERT thinks the SSL compression problem is fixed, but it isn't. They convinced CERT that it wasn't fixed and they issued a CVE. BREACH, breachattrack.com BREACH exploits the SSL response body (Accept-Encoding response, Content-Encoding). It takes advantage of the fact that the response is not compressed. BREACH uses gzip and needs fairly "stable" pages that are static for ~30 seconds. It needs attacker-supplied content (say from a web form or added to a URL parameter). BREACH listens to a session's requests and responses, then inserts extra requests and responses. Eventually, BREACH guesses a session's secret key. Can use compression to guess contents one byte at-a-time. For example, "Supersecret SupersecreX" (a wrong guess) compresses 10 bytes, and "Supersecret Supersecret" (a correct guess) compresses 11 bytes, so it can find each character by guessing every character. To start the guess, BREACH needs at least three known initial characters in the response sequence. Compression length then "leaks" information. Some roadblocks include no winners (all guesses wrong) or too many winners (multiple possibilities that compress the same). The solutions include: lookahead (guess 2 or 3 characters at-a-time instead of 1 character). Expensive rollback to last known conflict check compression ratio can brute-force first 3 "bootstrap" characters, if needed (expensive) block ciphers hide exact plain text length. Solution is to align response in advance to block size Mitigations length: use variable padding secrets: dynamic CSRF tokens per request secret: change over time separate secret to input-less servlets Future work eiter understand DEFLATE/GZIP HTTPS extensions Running at 99%: Surviving an Application DoS Ryan Huber Ryan Huber, Risk I/O Ryan first discussed various ways to do a denial of service (DoS) attack against web services. One usual method is to find a slow web page and do several wgets. Or download large files. Apache is not well suited at handling a large number of connections, but one can put something in front of it Can use Apache alternatives, such as nginx How to identify malicious hosts short, sudden web requests user-agent is obvious (curl, python) same url requested repeatedly no web page referer (not normal) hidden links. hide a link and see if a bot gets it restricted access if not your geo IP (unless the website is global) missing common headers in request regular timing first seen IP at beginning of attack count requests per hosts (usually a very large number) Use of captcha can mitigate attacks, but you'll lose a lot of genuine users. Bouncer, goo.gl/c2vyEc and www.github.com/rawdigits/Bouncer Bouncer is software written by Ryan in netflow. Bouncer has a small, unobtrusive footprint and detects DoS attempts. It closes blacklisted sockets immediately (not nice about it, no proper close connection). Aggregator collects requests and controls your web proxies. Need NTP on the front end web servers for clean data for use by bouncer. Bouncer is also useful for a popularity storm ("Slashdotting") and scraper storms. Future features: gzip collection data, documentation, consumer library, multitask, logging destroyed connections. Takeaways: DoS mitigation is easier with a complete picture Bouncer designed to make it easier to detect and defend DoS—not a complete cure Security Response in the Age of Mass Customized Attacks Peleus Uhley and Karthik Raman Peleus Uhley and Karthik Raman, Adobe ASSET, blogs.adobe.com/asset/ Peleus and Karthik talked about response to mass-customized exploits. Attackers behave much like a business. "Mass customization" refers to concept discussed in the book Future Perfect by Stan Davis of Harvard Business School. Mass customization is differentiating a product for an individual customer, but at a mass production price. For example, the same individual with a debit card receives basically the same customized ATM experience around the world. Or designing your own PC from commodity parts. Exploit kits are another example of mass customization. The kits support multiple browsers and plugins, allows new modules. Exploit kits are cheap and customizable. Organized gangs use exploit kits. A group at Berkeley looked at 77,000 malicious websites (Grier et al., "Manufacturing Compromise: The Emergence of Exploit-as-a-Service", 2012). They found 10,000 distinct binaries among them, but derived from only a dozen or so exploit kits. Characteristics of Mass Malware: potent, resilient, relatively low cost Technical characteristics: multiple OS, multipe payloads, multiple scenarios, multiple languages, obfuscation Response time for 0-day exploits has gone down from ~40 days 5 years ago to about ~10 days now. So the drive with malware is towards mass customized exploits, to avoid detection There's plenty of evicence that exploit development has Project Manager bureaucracy. They infer from the malware edicts to: support all versions of reader support all versions of windows support all versions of flash support all browsers write large complex, difficult to main code (8750 lines of JavaScript for example Exploits have "loose coupling" of multipe versions of software (adobe), OS, and browser. This allows specific attacks against specific versions of multiple pieces of software. Also allows exploits of more obscure software/OS/browsers and obscure versions. Gave examples of exploits that exploited 2, 3, 6, or 14 separate bugs. However, these complete exploits are more likely to be buggy or fragile in themselves and easier to defeat. Future research includes normalizing malware and Javascript. Conclusion: The coming trend is that mass-malware with mass zero-day attacks will result in mass customization of attacks. x86 Rewriting: Defeating RoP and other Shinanighans Richard Wartell Richard Wartell The attack vector we are addressing here is: First some malware causes a buffer overflow. The malware has no program access, but input access and buffer overflow code onto stack Later the stack became non-executable. The workaround malware used was to write a bogus return address to the stack jumping to malware Later came ASLR (Address Space Layout Randomization) to randomize memory layout and make addresses non-deterministic. The workaround malware used was to jump t existing code segments in the program that can be used in bad ways "RoP" is Return-oriented Programming attacks. RoP attacks use your own code and write return address on stack to (existing) expoitable code found in program ("gadgets"). Pinkie Pie was paid $60K last year for a RoP attack. One solution is using anti-RoP compilers that compile source code with NO return instructions. ASLR does not randomize address space, just "gadgets". IPR/ILR ("Instruction Location Randomization") randomizes each instruction with a virtual machine. Richard's goal was to randomize a binary with no source code access. He created "STIR" (Self-Transofrming Instruction Relocation). STIR disassembles binary and operates on "basic blocks" of code. The STIR disassembler is conservative in what to disassemble. Each basic block is moved to a random location in memory. Next, STIR writes new code sections with copies of "basic blocks" of code in randomized locations. The old code is copied and rewritten with jumps to new code. the original code sections in the file is marked non-executible. STIR has better entropy than ASLR in location of code. Makes brute force attacks much harder. STIR runs on MS Windows (PEM) and Linux (ELF). It eliminated 99.96% or more "gadgets" (i.e., moved the address). Overhead usually 5-10% on MS Windows, about 1.5-4% on Linux (but some code actually runs faster!). The unique thing about STIR is it requires no source access and the modified binary fully works! Current work is to rewrite code to enforce security policies. For example, don't create a *.{exe,msi,bat} file. Or don't connect to the network after reading from the disk. Clowntown Express: interesting bugs and running a bug bounty program Collin Greene Collin Greene, Facebook Collin talked about Facebook's bug bounty program. Background at FB: FB has good security frameworks, such as security teams, external audits, and cc'ing on diffs. But there's lots of "deep, dark, forgotten" parts of legacy FB code. Collin gave several examples of bountied bugs. Some bounty submissions were on software purchased from a third-party (but bounty claimers don't know and don't care). We use security questions, as does everyone else, but they are basically insecure (often easily discoverable). Collin didn't expect many bugs from the bounty program, but they ended getting 20+ good bugs in first 24 hours and good submissions continue to come in. Bug bounties bring people in with different perspectives, and are paid only for success. Bug bounty is a better use of a fixed amount of time and money versus just code review or static code analysis. The Bounty program started July 2011 and paid out $1.5 million to date. 14% of the submissions have been high priority problems that needed to be fixed immediately. The best bugs come from a small % of submitters (as with everything else)—the top paid submitters are paid 6 figures a year. Spammers like to backstab competitors. The youngest sumitter was 13. Some submitters have been hired. Bug bounties also allows to see bugs that were missed by tools or reviews, allowing improvement in the process. Bug bounties might not work for traditional software companies where the product has release cycle or is not on Internet. Active Fingerprinting of Encrypted VPNs Anna Shubina Anna Shubina, Dartmouth Institute for Security, Technology, and Society (I missed the start of her talk because another track went overtime. But I have the DVD of the talk, so I'll expand later) IPsec leaves fingerprints. Using netcat, one can easily visually distinguish various crypto chaining modes just from packet timing on a chart (example, DES-CBC versus AES-CBC) One can tell a lot about VPNs just from ping roundtrips (such as what router is used) Delayed packets are not informative about a network, especially if far away from the network More needed to explore about how TCP works in real life with respect to timing Making Attacks Go Backwards Fuzzynop FuzzyNop, Mandiant This talk is not about threat attribution (finding who), product solutions, politics, or sales pitches. But who are making these malware threats? It's not a single person or group—they have diverse skill levels. There's a lot of fat-fingered fumblers out there. Always look for low-hanging fruit first: "hiding" malware in the temp, recycle, or root directories creation of unnamed scheduled tasks obvious names of files and syscalls ("ClearEventLog") uncleared event logs. Clearing event log in itself, and time of clearing, is a red flag and good first clue to look for on a suspect system Reverse engineering is hard. Disassembler use takes practice and skill. A popular tool is IDA Pro, but it takes multiple interactive iterations to get a clean disassembly. Key loggers are used a lot in targeted attacks. They are typically custom code or built in a backdoor. A big tip-off is that non-printable characters need to be printed out (such as "[Ctrl]" "[RightShift]") or time stamp printf strings. Look for these in files. Presence is not proof they are used. Absence is not proof they are not used. Java exploits. Can parse jar file with idxparser.py and decomile Java file. Java typially used to target tech companies. Backdoors are the main persistence mechanism (provided externally) for malware. Also malware typically needs command and control. Application of Artificial Intelligence in Ad-Hoc Static Code Analysis John Ashaman John Ashaman, Security Innovation Initially John tried to analyze open source files with open source static analysis tools, but these showed thousands of false positives. Also tried using grep, but tis fails to find anything even mildly complex. So next John decided to write his own tool. His approach was to first generate a call graph then analyze the graph. However, the problem is that making a call graph is really hard. For example, one problem is "evil" coding techniques, such as passing function pointer. First the tool generated an Abstract Syntax Tree (AST) with the nodes created from method declarations and edges created from method use. Then the tool generated a control flow graph with the goal to find a path through the AST (a maze) from source to sink. The algorithm is to look at adjacent nodes to see if any are "scary" (a vulnerability), using heuristics for search order. The tool, called "Scat" (Static Code Analysis Tool), currently looks for C# vulnerabilities and some simple PHP. Later, he plans to add more PHP, then JSP and Java. For more information see his posts in Security Innovation blog and NRefactory on GitHub. Mask Your Checksums—The Gorry Details Eric (XlogicX) Davisson Eric (XlogicX) Davisson Sometimes in emailing or posting TCP/IP packets to analyze problems, you may want to mask the IP address. But to do this correctly, you need to mask the checksum too, or you'll leak information about the IP. Problem reports found in stackoverflow.com, sans.org, and pastebin.org are usually not masked, but a few companies do care. If only the IP is masked, the IP may be guessed from checksum (that is, it leaks data). Other parts of packet may leak more data about the IP. TCP and IP checksums both refer to the same data, so can get more bits of information out of using both checksums than just using one checksum. Also, one can usually determine the OS from the TTL field and ports in a packet header. If we get hundreds of possible results (16x each masked nibble that is unknown), one can do other things to narrow the results, such as look at packet contents for domain or geo information. With hundreds of results, can import as CSV format into a spreadsheet. Can corelate with geo data and see where each possibility is located. Eric then demoed a real email report with a masked IP packet attached. Was able to find the exact IP address, given the geo and university of the sender. Point is if you're going to mask a packet, do it right. Eric wouldn't usually bother, but do it correctly if at all, to not create a false impression of security. Adventures with weird machines thirty years after "Reflections on Trusting Trust" Sergey Bratus Sergey Bratus, Dartmouth College (and Julian Bangert and Rebecca Shapiro, not present) "Reflections on Trusting Trust" refers to Ken Thompson's classic 1984 paper. "You can't trust code that you did not totally create yourself." There's invisible links in the chain-of-trust, such as "well-installed microcode bugs" or in the compiler, and other planted bugs. Thompson showed how a compiler can introduce and propagate bugs in unmodified source. But suppose if there's no bugs and you trust the author, can you trust the code? Hell No! There's too many factors—it's Babylonian in nature. Why not? Well, Input is not well-defined/recognized (code's assumptions about "checked" input will be violated (bug/vunerabiliy). For example, HTML is recursive, but Regex checking is not recursive. Input well-formed but so complex there's no telling what it does For example, ELF file parsing is complex and has multiple ways of parsing. Input is seen differently by different pieces of program or toolchain Any Input is a program input executes on input handlers (drives state changes & transitions) only a well-defined execution model can be trusted (regex/DFA, PDA, CFG) Input handler either is a "recognizer" for the inputs as a well-defined language (see langsec.org) or it's a "virtual machine" for inputs to drive into pwn-age ELF ABI (UNIX/Linux executible file format) case study. Problems can arise from these steps (without planting bugs): compiler linker loader ld.so/rtld relocator DWARF (debugger info) exceptions The problem is you can't really automatically analyze code (it's the "halting problem" and undecidable). Only solution is to freeze code and sign it. But you can't freeze everything! Can't freeze ASLR or loading—must have tables and metadata. Any sufficiently complex input data is the same as VM byte code Example, ELF relocation entries + dynamic symbols == a Turing Complete Machine (TM). @bxsays created a Turing machine in Linux from relocation data (not code) in an ELF file. For more information, see Rebecca "bx" Shapiro's presentation from last year's Toorcon, "Programming Weird Machines with ELF Metadata" @bxsays did same thing with Mach-O bytecode Or a DWARF exception handling data .eh_frame + glibc == Turning Machine X86 MMU (IDT, GDT, TSS): used address translation to create a Turning Machine. Page handler reads and writes (on page fault) memory. Uses a page table, which can be used as Turning Machine byte code. Example on Github using this TM that will fly a glider across the screen Next Sergey talked about "Parser Differentials". That having one input format, but two parsers, will create confusion and opportunity for exploitation. For example, CSRs are parsed during creation by cert requestor and again by another parser at the CA. Another example is ELF—several parsers in OS tool chain, which are all different. Can have two different Program Headers (PHDRs) because ld.so parses multiple PHDRs. The second PHDR can completely transform the executable. This is described in paper in the first issue of International Journal of PoC. Conclusions trusting computers not only about bugs! Bugs are part of a problem, but no by far all of it complex data formats means bugs no "chain of trust" in Babylon! (that is, with parser differentials) we need to squeeze complexity out of data until data stops being "code equivalent" Further information See and langsec.org. USENIX WOOT 2013 (Workshop on Offensive Technologies) for "weird machines" papers and videos.

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  • Is there any practical use for the empty type in Common Lisp?

    - by Pedro Rodrigues
    The Common Lisp spec states that nil is the name of the empty type, but I've never found any situation in Common Lisp where I felt like the empty type was useful/necessary. Is it there just for completeness sake (and removing it wouldn't cause any harm to anyone)? Or is there really some practical use for the empty type in Common Lisp? If yes, then I would prefer an answer with code example. For example, in Haskell the empty type can be used when binding foreign data structures, to make sure that no one tries to create values of that type without using the data structure's foreign interface (although in this case, the type is not really empty).

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  • Blueprints for Oracle NoSQL Database

    - by dan.mcclary
    I think that some of the most interesting analytic problems are graph problems.  I'm always interested in new ways to store and access graphs.  As such, I really like the work being done by Tinkerpop to create Open Source Software to make property graphs more accessible over a wide variety of datastores.  Since key-value stores like Oracle NoSQL Database are well-suited to storing property graphs, I decided to extend the Blueprints API to work with it.  Below I'll discuss some of the implementation details, but you can check out the finished product here: http://github.com/dwmclary/blueprints-oracle-nosqldb.  What's in a Property Graph?  In the most general sense, a graph is just a collection of vertices and edges.  Vertices and edges can have properties: weights, names, or any number of other traits.  In an undirected graph, edges connect vertices without direction.  A directed graph specifies that all edges have a head and a tail --- a direction.  A multi-graph allows multiple edges to connect two vertices.  A "property graph" encompasses all of these traits. Key-Value Stores for Property Graphs Key-Value stores like Oracle NoSQL Database tend to be ideal for implementing property graphs.  First, if any vertex or edge can have any number of traits, we can treat it as a hash map.  For example: Vertex["name"] = "Mary" Vertex["age"] = 28 Vertex["ID"] = 12345  and so on.  This is a natural key-value relationship: the key "name" maps to the value "Mary."  Moreover if we maintain two hash maps, one for vertex objects and one for edge objects, we've essentially captured the graph.  As such, any scalable key-value store is fertile ground for planting graphs. Oracle NoSQL Database as a Scalable Graph Database While Oracle NoSQL Database offers useful features like tunable consistency, what lends it to storing property graphs is the storage guarantees around its key structure.  Keys in Oracle NoSQL Database are divided into two parts: a major key and a minor key.  The storage guarantee is simple.  Major keys will be distributed across storage nodes, which could encompass a large number of servers.  However, all minor keys which are children of a given major key are guaranteed to be stored on the same storage node.  For example, the vertices: /Personnel/Vertex/1  and /Personnel/Vertex/2 May be stored on different servers, but /Personnel/Vertex/1-/name and  /Personnel/Vertex/1-/age will always be on the same server.  This means that we can structure our graph database such that retrieving all the properties for a vertex or edge requires I/O from only a single storage node.  Moreover, Oracle NoSQL Database provides a storeIterator which allows us to store a huge number of vertices and edges in a scalable fashion.  By storing the vertices and edges as major keys, we guarantee that they are distributed evenly across all storage nodes.  At the same time we can use a partial major key to iterate over all the vertices or edges (e.g. we search over /Personnel/Vertex to iterate over all vertices). Fork It! The Blueprints API and Oracle NoSQL Database present a great way to get started using a scalable key-value database to store and access graph data.  However, a graph store isn't useful without a good graph to work on.  I encourage you to fork or pull the repository, store some data, and try using Gremlin or any other language to explore.

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  • 2D Tile Based Collision Detection

    - by MrPlosion1243
    There are a lot of topics about this and it seems each one addresses a different problem, this topic does the same. I was looking into tile collision detection and found this where David Gouveia explains a great way to get around the person's problem by separating the two axis. So I implemented the solution and it all worked perfectly from all the testes I through at it. Then I implemented more advanced platforming physics and the collision detection broke down. Unfortunately I have not been able to get it to work again which is where you guys come in :)! I will present the code first: public void Update(GameTime gameTime) { if(Input.GetKeyDown(Keys.A)) { velocity.X -= moveAcceleration; } else if(Input.GetKeyDown(Keys.D)) { velocity.X += moveAcceleration; } if(Input.GetKeyDown(Keys.Space)) { if((onGround && isPressable) || (!onGround && airTime <= maxAirTime && isPressable)) { onGround = false; airTime += (float)gameTime.ElapsedGameTime.TotalSeconds; velocity.Y = initialJumpVelocity * (1.0f - (float)Math.Pow(airTime / maxAirTime, Math.PI)); } } else if(Input.GetKeyReleased(Keys.Space)) { isPressable = false; } if(onGround) { velocity.X *= groundDrag; velocity.Y = 0.0f; } else { velocity.X *= airDrag; velocity.Y += gravityAcceleration; } velocity.Y = MathHelper.Clamp(velocity.Y, -maxFallSpeed, maxFallSpeed); velocity.X = MathHelper.Clamp(velocity.X, -maxMoveSpeed, maxMoveSpeed); position += velocity * (float)gameTime.ElapsedGameTime.TotalSeconds; position = new Vector2((float)Math.Round(position.X), (float)Math.Round(position.Y)); if(Math.Round(velocity.X) != 0.0f) { HandleCollisions2(Direction.Horizontal); } if(Math.Round(velocity.Y) != 0.0f) { HandleCollisions2(Direction.Vertical); } } private void HandleCollisions2(Direction direction) { int topTile = (int)Math.Floor((float)Bounds.Top / Tile.PixelTileSize); int bottomTile = (int)Math.Ceiling((float)Bounds.Bottom / Tile.PixelTileSize) - 1; int leftTile = (int)Math.Floor((float)Bounds.Left / Tile.PixelTileSize); int rightTile = (int)Math.Ceiling((float)Bounds.Right / Tile.PixelTileSize) - 1; for(int x = leftTile; x <= rightTile; x++) { for(int y = topTile; y <= bottomTile; y++) { Rectangle tileBounds = new Rectangle(x * Tile.PixelTileSize, y * Tile.PixelTileSize, Tile.PixelTileSize, Tile.PixelTileSize); Vector2 depth; if(Tile.IsSolid(x, y) && Intersects(tileBounds, direction, out depth)) { if(direction == Direction.Horizontal) { position.X += depth.X; } else { onGround = true; isPressable = true; airTime = 0.0f; position.Y += depth.Y; } } } } } From the code you can see when velocity.X is not equal to zero the HandleCollisions() Method is called along the horizontal axis and likewise for the vertical axis. When velocity.X is not equal to zero and velocity.Y is equal to zero it works fine. When velocity.Y is not equal to zero and velocity.X is equal to zero everything also works fine. However when both axis are not equal to zero that's when it doesn't work and I don't know why. I basically teleport to the left side of a tile when both axis are not equal to zero and there is a air block next to me. Hopefully someone can see the problem with this because I sure don't as far as I'm aware nothing has even changed from what I'm doing to what the linked post's solution is doing. Thanks.

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  • Oracle GoldenGate Active-Active Part 1

    - by Nick_W
    My name is Nick Wagner, and I'm a recent addition to the Oracle Maximum Availability Architecture (MAA) product management team.  I've spent the last 15+ years working on database replication products, and I've spent the last 10 years working on the Oracle GoldenGate product.  So most of my posting will probably be focused on OGG.  One question that comes up all the time is around active-active replication with Oracle GoldenGate.  How do I know if my application is a good fit for active-active replication with GoldenGate?   To answer that, it really comes down to how you plan on handling conflict resolution.  I will delve into topology and deployment in a later blog, but here is a simple architecture: The two most common resolution routines are host based resolution and timestamp based resolution. Host based resolution is used less often, but works with the fewest application changes.  Think of it like this: any transactions from SystemA always take precedence over any transactions from SystemB.  If there is a conflict on SystemB, then the record from SystemA will overwrite it.  If there is a conflict on SystemA, then it will be ignored.  It is quite a bit less restrictive, and in most cases, as long as all the tables have primary keys, host based resolution will work just fine.  Timestamp based resolution, on the other hand, is a little trickier. In this case, you can decide which record is overwritten based on timestamps. For example, does the older record get overwritten with the newer record?  Or vice-versa?  This method not only requires primary keys on every table, but it also requires every table to have a timestamp/date column that is updated each time a record is inserted or updated on the table.  Most homegrown applications can always be customized to include these requirements, but it's a little more difficult with 3rd party applications, and might even be impossible for large ERP type applications.  If your database has these features - whether it’s primary keys for host based resolution, or primary keys and timestamp columns for timestamp based resolution - then your application could be a great candidate for active-active replication.  But table structure is not the only requirement.  The other consideration applies when there is a conflict; i.e., do I need to perform any notification or track down the user that had their data overwritten?  In most cases, I don't think it's necessary, but if it is required, OGG can always create an exceptions table that contains all of the overwritten transactions so that people can be notified. It's a bit of extra work to implement this type of option, but if the business requires it, then it can be done. Unless someone is constantly monitoring this exception table or has an automated process in dealing with exceptions, there will be a delay in getting a response back to the end user. Ideally, when setting up active-active resolution we can include some simple procedural steps or configuration options that can reduce, or in some cases eliminate the potential for conflicts.  This makes the whole implementation that much easier and foolproof.  And I'll cover these in my next blog. 

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  • 5 Things SQL Server should get rid of

    - by Jonathan Kehayias
    Paul Randal ( blog | twitter ) started a new meme last night with his blog post " What 5 things should SQL Server get rid of? " A few bloggers have posted their top 5 lists, so here is mine. Creating Foreign Keys without mentioning Indexes This is probably a performance tuning consultants favorite.  I know that Greg Low has blogged about this in the past (see Indexing Foreign Keys - should SQL Server do that automatically? ) and back then, and now I still do think this should be an...(read more)

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  • Vertical Scrolling In Tile Based XNA Platformer

    - by alec100_94
    I'm making a 2D platformer in XNA 4.0. I have created a working tile engine, which works well for my purposes, and Horizontal Scrolling works flawlessly, however I am having great trouble with Vertical scrolling. I Basically want the camera to scroll up (world to scroll down) when the player reaches a certain Y co-ordinate, and I would also like to automatically scroll back down if coming down, and that co-ordinate is passed. My biggest problem is I have no real way of detecting the direction the player is moving in using only the Y Co-ord. Here Is My Code Code For The Camera Class (which appears to be a very different approach to most camera classes I have seen). using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; namespace Marvin { class Camera : TileEngine { public static bool startReached; public static bool endReached; public static void MoveRight(float speed = 2) { //Moves The Position of Each Tile Right foreach (Tile t in tiles) { if(t!=null) { t.position.X -= speed; } } } public static void MoveLeft(float speed = 2) { //Moves The Position of Each Tile Right foreach (Tile t in tiles) { if(t!=null) { t.position.X += speed; } } } public static void MoveUp(float speed = 2) { foreach (Tile t in tiles) { if(t!=null) { t.position.Y += speed; } } } public static void MoveDown(float speed = 2) { foreach (Tile t in tiles) { if(t!=null) { t.position.Y -= speed; } } } public static void Restrain() { if(tiles.Last().position.X<Main.graphics.PreferredBackBufferWidth-tiles.Last().size.X) { MoveLeft(); endReached = true; } else { endReached = false; } if(tiles[1].position.X>0) { MoveRight(); startReached = true;} else { startReached = false; } } } } Here is My Player Code for Left and Right Scrolling/Moving if (Main.currentKeyState.IsKeyDown(Keys.Right)) { Camera.MoveRight(); if(Camera.endReached) { MoveRight(2); } else { if(marvin.GetRectangle().X!=Main.graphics.PreferredBackBufferWidth-(marvin.GetRectangle().X+marvin.GetRectangle().Width)) { MoveRight(2); Camera.MoveLeft(); } } } if(Main.currentKeyState.IsKeyDown(Keys.Left)) { Camera.MoveLeft(); if(Camera.startReached) { MoveLeft(2); } else { if(marvin.GetRectangle().X!=Main.graphics.PreferredBackBufferWidth-(marvin.GetRectangle().X+marvin.GetRectangle().Width)) { MoveLeft(2); Camera.MoveRight(); } } } Camera.Restrain(); if(marvin.GetRectangle().X>Main.graphics.PreferredBackBufferWidth-marvin.GetRectangle().Width) { MoveLeft(2); } if(marvin.GetRectangle().X<0) { MoveRight(2); } And Here Is My Player Jumping/Falling Code which may cause some conflicts with the vertical camera movement. if (!jumping) { if(!TileEngine.TopOfTileCollidingWith(footBounds)) { MoveDown(5); } else { if(marvin.GetRectangle().Y != TileEngine.LastPlatformStoodOnTop()-marvin.GetRectangle().Height) { float difference = (TileEngine.LastPlatformStoodOnTop()-marvin.GetRectangle().Height) - (marvin.GetRectangle().Y); marvin.SetRectangle(marvin.GetRectangle().X,(int)(marvin.GetRectangle().Y+difference)); armR.SetRectangle(armR.GetRectangle().X,(int)(armR.GetRectangle().Y+difference)); armL.SetRectangle(armL.GetRectangle().X,(int)(armL.GetRectangle().Y+difference)); eyeL.SetRectangle(eyeL.GetRectangle().X,(int)(eyeL.GetRectangle().Y+difference)); eyeR.SetRectangle(eyeR.GetRectangle().X,(int)(eyeR.GetRectangle().Y+difference)); } } } if (Main.currentKeyState.IsKeyDown(Keys.Up) && Main.previousKeyState.IsKeyUp(Keys.Up) && TileEngine.TopOfTileCollidingWith(footBounds)) { jumping = true; } if(jumping) { if(TileEngine.LastPlatformStoodOnTop()>0 && (TileEngine.LastPlatformStoodOnTop() - footBounds.Bottom)<120) { MoveUp(5); } else { jumping = false; } } All player code I have tried for vertical movements has failed, or caused weird results (like falling through platforms), and most have been a variation on the method I described above, hence I have not included it. I would really appreciate some help implementing a simple vertical scrolling into this game, Thanks.

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  • Breaking 1NF to model subset constraints. Does this sound sane?

    - by Chris Travers
    My first question here. Appologize if it is in the wrong forum but this seems pretty conceptual. I am looking at doing something that goes against conventional wisdom and want to get some feedback as to whether this is totally insane or will result in problems, so critique away! I am on PostgreSQL 9.1 but may be moving to 9.2 for this part of this project. To re-iterate: Does it seem sane to break 1NF in this way? I am not looking for debugging code so much as where people see problems that this might lead. The Problem In double entry accounting, financial transactions are journal entries with an arbitrary number of lines. Each line has either a left value (debit) or a right value (credit) which can be modelled as a single value with negatives as debits and positives as credits or vice versa. The sum of all debits and credits must equal zero (so if we go with a single amount field, sum(amount) must equal zero for each financial journal entry). SQL-based databases, pretty much required for this sort of work, have no way to express this sort of constraint natively and so any approach to enforcing it in the database seems rather complex. The Write Model The journal entries are append only. There is a possibility we will add a delete model but it will be subject to a different set of restrictions and so is not applicable here. If and when we allow deletes, we will probably do them using a simple ON DELETE CASCADE designation on the foreign key, and require that deletes go through a dedicated stored procedure which can enforce the other constraints. So inserts and selects have to be accommodated but updates and deletes do not for this task. My Proposed Solution My proposed solution is to break first normal form and model constraints on arrays of tuples, with a trigger that breaks the rows out into another table. CREATE TABLE journal_line ( entry_id bigserial primary key, account_id int not null references account(id), journal_entry_id bigint not null, -- adding references later amount numeric not null ); I would then add "table methods" to extract debits and credits for reporting purposes: CREATE OR REPLACE FUNCTION debits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount < 0 THEN $1.amount * -1 ELSE NULL END; $$; CREATE OR REPLACE FUNCTION credits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount > 0 THEN $1.amount ELSE NULL END; $$; Then the journal entry table (simplified for this example): CREATE TABLE journal_entry ( entry_id bigserial primary key, -- no natural keys :-( journal_id int not null references journal(id), date_posted date not null, reference text not null, description text not null, journal_lines journal_line[] not null ); Then a table method and and check constraints: CREATE OR REPLACE FUNCTION running_total(journal_entry) returns numeric language sql immutable as $$ SELECT sum(amount) FROM unnest($1.journal_lines); $$; ALTER TABLE journal_entry ADD CONSTRAINT CHECK (((journal_entry.running_total) = 0)); ALTER TABLE journal_line ADD FOREIGN KEY journal_entry_id REFERENCES journal_entry(entry_id); And finally we'd have a breakout trigger: CREATE OR REPLACE FUNCTION je_breakout() RETURNS TRIGGER LANGUAGE PLPGSQL AS $$ BEGIN IF TG_OP = 'INSERT' THEN INSERT INTO journal_line (journal_entry_id, account_id, amount) SELECT NEW.id, account_id, amount FROM unnest(NEW.journal_lines); RETURN NEW; ELSE RAISE EXCEPTION 'Operation Not Allowed'; END IF; END; $$; And finally CREATE TRIGGER AFTER INSERT OR UPDATE OR DELETE ON journal_entry FOR EACH ROW EXECUTE_PROCEDURE je_breaout(); Of course the example above is simplified. There will be a status table that will track approval status allowing for separation of duties, etc. However the goal here is to prevent unbalanced transactions. Any feedback? Does this sound entirely insane? Standard Solutions? In getting to this point I have to say I have looked at four different current ERP solutions to this problems: Represent every line item as a debit and a credit against different accounts. Use of foreign keys against the line item table to enforce an eventual running total of 0 Use of constraint triggers in PostgreSQL Forcing all validation here solely through the app logic. My concerns are that #1 is pretty limiting and very hard to audit internally. It's not programmer transparent and so it strikes me as being difficult to work with in the future. The second strikes me as being very complex and required a series of contraints and foreign keys against self to make work, and therefore it strikes me as complex, hard to sort out at least in my mind, and thus hard to work with. The fourth could be done as we force all access through stored procedures anyway and this is the most common solution (have the app total things up and throw an error otherwise). However, I think proof that a constraint is followed is superior to test cases, and so the question becomes whether this in fact generates insert anomilies rather than solving them. If this is a solved problem it isn't the case that everyone agrees on the solution....

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  • ADF Business Components

    - by Arda Eralp
    ADF Business Components and JDeveloper simplify the development, delivery, and customization of business applications for the Java EE platform. With ADF Business Components, developers aren't required to write the application infrastructure code required by the typical Java EE application to: Connect to the database Retrieve data Lock database records Manage transactions   ADF Business Components addresses these tasks through its library of reusable software components and through the supporting design time facilities in JDeveloper. Most importantly, developers save time using ADF Business Components since the JDeveloper design time makes typical development tasks entirely declarative. In particular, JDeveloper supports declarative development with ADF Business Components to: Author and test business logic in components which automatically integrate with databases Reuse business logic through multiple SQL-based views of data, supporting different application tasks Access and update the views from browser, desktop, mobile, and web service clients Customize application functionality in layers without requiring modification of the delivered application The goal of ADF Business Components is to make the business services developer more productive.   ADF Business Components provides a foundation of Java classes that allow your business-tier application components to leverage the functionality provided in the following areas: Simplifying Data Access Design a data model for client displays, including only necessary data Include master-detail hierarchies of any complexity as part of the data model Implement end-user Query-by-Example data filtering without code Automatically coordinate data model changes with business services layer Automatically validate and save any changes to the database   Enforcing Business Domain Validation and Business Logic Declaratively enforce required fields, primary key uniqueness, data precision-scale, and foreign key references Easily capture and enforce both simple and complex business rules, programmatically or declaratively, with multilevel validation support Navigate relationships between business domain objects and enforce constraints related to compound components   Supporting Sophisticated UIs with Multipage Units of Work Automatically reflect changes made by business service application logic in the user interface Retrieve reference information from related tables, and automatically maintain the information when the user changes foreign-key values Simplify multistep web-based business transactions with automatic web-tier state management Handle images, video, sound, and documents without having to use code Synchronize pending data changes across multiple views of data Consistently apply prompts, tooltips, format masks, and error messages in any application Define custom metadata for any business components to support metadata-driven user interface or application functionality Add dynamic attributes at runtime to simplify per-row state management   Implementing High-Performance Service-Oriented Architecture Support highly functional web service interfaces for business integration without writing code Enforce best-practice interface-based programming style Simplify application security with automatic JAAS integration and audit maintenance "Write once, run anywhere": use the same business service as plain Java class, EJB session bean, or web service   Streamlining Application Customization Extend component functionality after delivery without modifying source code Globally substitute delivered components with extended ones without modifying the application   ADF Business Components implements the business service through the following set of cooperating components: Entity object An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. These are basically your 1 to 1 representation of a database table. Each table in the database will have 1 and only 1 EO. The EO contains the mapping between columns and attributes. EO's also contain the business logic and validation. These are you core data services. They are responsible for updating, inserting and deleting records. The Attributes tab displays the actual mapping between attributes and columns, the mapping has following fields: Name : contains the name of the attribute we expose in our data model. Type : defines the data type of the attribute in our application. Column : specifies the column to which we want to map the attribute with Column Type : contains the type of the column in the database   View object A view object represents a SQL query. You use the full power of the familiar SQL language to join, filter, sort, and aggregate data into exactly the shape required by the end-user task. The attributes in the View Objects are actually coming from the Entity Object. In the end the VO will generate a query but you basically build a VO by selecting which EO need to participate in the VO and which attributes of those EO you want to use. That's why you have the Entity Usage column so you can see the relation between VO and EO. In the query tab you can clearly see the query that will be generated for the VO. At this stage we don't need it and just use it for information purpose. In later stages we might use it. Application module An application module is the controller of your data layer. It is responsible for keeping hold of the transaction. It exposes the data model to the view layer. You expose the VO's through the Application Module. This is the abstraction of your data layer which you want to show to the outside word.It defines an updatable data model and top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task. While the base components handle all the common cases through built-in behavior, customization is always possible and the default behavior provided by the base components can be easily overridden or augmented. When you create EO's, a foreign key will be translated into an association in our model. It defines the type of relation and who is the master and child as well as how the visibility of the association looks like. A similar concept exists to identify relations between view objects. These are called view links. These are almost identical as association except that a view link is based upon attributes defined in the view object. It can also be based upon an association. Here's a short summary: Entity Objects: representations of tables Association: Relations between EO's. Representations of foreign keys View Objects: Logical model View Links: Relationships between view objects Application Model: interface to your application  

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  • joomla ACL :: two groups permissions conflict

    - by semyon
    I have several user groups on my website, like: Site Staff Departments -- History department -- Physics department -- Foreign languages department -- IT department etc I also have several categories, like: News About ... Departments -- History department -- Physics department -- Foreign languages department -- IT department etc Users in Site Staff group can edit entire site, except for Departments categories (I've set Deny permission for it). Each Department user group can edit only its corresponding category. I have successfully implemented all this. The question is: If a user belongs to two groups (Site Staff and Physics department - for instance) - he should be able to edit the whole site, except for Departments category. And also he should be able to edit Physics department category - this is what I cannot implement. Can you suggest any ideas?

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  • About cdn architecture to route way

    - by Tony Lee
    Our web system, use the third-party cdn service. Assume that the user set the local dns with the googledns or opendns to visit our web sites, so cdn service will select the closest cdn proxy node. all right, but in fact the user's actual access position might outside there, cdn service may chose the one furthest away from the user node, so static resource access slower.. At present, my idea is if user local set dns server with googledns, and then first one we get the actual ip address of the user, tracerote to test a best routing lines, set up a cookie in user browser, and then set 302 header for response to jump to the which best cdn node. Whether the user's browser side traceroute tool can provide the best route decision-making ? Because we find that, once the user to set local dns server with the foreign network segment, for example : set dns with 8.8.8.8, so cdn routing will choose the foreign service node.

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