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Automatically add links to class source files under a specified directory of another project in Visu

- by Binary255

I want to share some class source files between two projects in Visual Studio 2008. I can't create a project for the common parts and reference it (see my comment if you are curious to why). I've managed to share some source files, but it could be a lot more neat. I've created a test solution called Commonality. The Solution Explorer of the Commonality solution which contains project One and Two: What I like: All class files under the Common folder of project One are automatically added to project Two by linking. It's mostly the same as if I would have chosen Add / Existing Item... : Add As Link on each new class source file. It's clear that these files have been linked in. The shortcut arrow symbol is marking each file icon. What I do not like: The file and folder tree structure under Common of project One isn't included. It's all flat. The linked source files are shown under the project root of project Two. It would look much less cluttered if they were located under Common like in project One. The file tree structure of the Commonality solution which contains project One and Two: $ tree /F /A Folder PATH listing for volume Cystem Volume serial number is 0713370 1337:F6A4 C:. | Commonality.sln | +---One | | One.cs | | One.csproj | | | +---bin | | \---Debug | | One.vshost.exe | | One.vshost.exe.manifest | | | +---Common | | | Common.cs | | | CommonTwo.cs | | | | | \---SubCommon | | CommonThree.cs | | | +---obj | | \---Debug | | +---Refactor | | \---TempPE | \---Properties | AssemblyInfo.cs | \---Two | Two.cs | Two.csproj | Two.csproj.user | Two.csproj~ | +---bin | \---Debug +---obj | \---Debug | +---Refactor | \---TempPE \---Properties AssemblyInfo.cs And the relevant part of project Two's project file Two.csproj: <ItemGroup> <Compile Include="..\One\Common\**\*.cs"> </Compile> <Compile Include="Two.cs" /> <Compile Include="Properties\AssemblyInfo.cs" /> </ItemGroup> How do I address what I do not like, while keeping what I like?

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Avoid the collapsing effect on TreeView after updating data

- by Manolete

I have a TreeView used to display events. It works great, however every time new events are coming in and populating the tree collapse the tree again to the original position. That is very annoying when the refresh time is less than 1 second and it does not allow the user to interact with the items of the tree. Is there any way to avoid this behaviour? <TreeView Margin="1" BorderThickness="0" Name="eventsTree" ItemsSource="{Binding EventAlertContainers}" Background="#00000000" ScrollViewer.VerticalScrollBarVisibility="Auto" FontSize="14" VirtualizingStackPanel.IsVirtualizing="True"> <TreeView.Resources> <HierarchicalDataTemplate DataType="{x:Type C:EventAlertContainer}" ItemsSource="{Binding EventAlerts}"> <StackPanel Orientation="Horizontal"> <Image Width="20" Height="20" Margin="3,0" Source="Resources\Process_info_32.png" /> <TextBlock FontWeight="Bold" FontSize="16" Text="{Binding Description}" /> </StackPanel> </HierarchicalDataTemplate> <HierarchicalDataTemplate DataType="{x:Type C:EventAlert}" ItemsSource="{Binding Events}"> <StackPanel Orientation="Horizontal"> <Image Width="20" Height="20" Margin="0,0" Source="Resources\clock2_32.jpg" /> <TextBlock FontWeight="DemiBold" FontSize="14" Text="{Binding Name}" /> </StackPanel> </HierarchicalDataTemplate> <HierarchicalDataTemplate DataType="{x:Type C:Event}"> <StackPanel Orientation="Horizontal"> <Image Width="20" Height="20" Margin="0,0" Source="Resources\Task_32.png" /> <StackPanel Orientation="Vertical"> <TextBlock FontSize="12" Text="{Binding Name}" /> </StackPanel> </StackPanel> </HierarchicalDataTemplate> </TreeView.Resources> </TreeView>

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Returning recursive ternary freaks out

- by David Titarenco

Hi, assume this following function: int binaryTree::findHeight(node *n) { if (n == NULL) { return 0; } else { return 1 + max(findHeight(n->left), findHeight(n->right)); } } Pretty standard recursive treeHeight function for a given binary search tree binaryTree. Now, I was helping a friend (he's taking an algorithms course), and I ran into some weird issue with this function that I couldn't 100% explain to him. With max being defined as max(a,b) ((a)>(b)?(a):(b)) (which happens to be the max definition in windef.h), the recursive function freaks out (it runs something like n^n times where n is the tree height). This obviously makes checking the height of a tree with 3000 elements take very, very long. However, if max is defined via templating, like std does it, everything is okay. So using std::max fixed his problem. I just want to know why. Also, why does the countLeaves function work fine, using the same programmatic recursion? int binaryTree::countLeaves(node *n) { if (n == NULL) { return 0; } else if (n->left == NULL && n->right == NULL) { return 1; } else { return countLeaves(n->left) + countLeaves(n->right); } } Is it because in returning the ternary function, the values a => countLeaves(n->left) and b => countLeaves(n->right) were recursively double called simply because they were the resultants? Thank you!

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Can ElementTree be told to preserve the order of attributes?

- by dmckee

I've written a fairly simple filter in python using ElementTree to munge the contexts of some xml files. And it works, more or less. But it reorders the attributes of various tags, and I'd like it to not do that. Does anyone know a switch I can throw to make it keep them in specified order? Context for this I'm working with and on a particle physics tool that has a complex, but oddly limited configuration system based on xml files. Among the many things setup that way are the paths to various static data files. These paths are hardcoded into the existing xml and there are no facilities for setting or varying them based on environment variables, and in our local installation they are necessarily in a different place. This isn't a disaster because the combined source- and build-control tool we're using allows us to shadow certain files with local copies. But even thought the data fields are static the xml isn't, so I've written a script for fixing the paths, but with the attribute rearrangement diffs between the local and master versions are harder to read than necessary. This is my first time taking ElementTree for a spin (and only my fifth or sixth python project) so maybe I'm just doing it wrong. Abstracted for simplicity the code looks like this: tree = elementtree.ElementTree.parse(inputfile) i = tree.getiterator() for e in i: e.text = filter(e.text) tree.write(outputfile) Reasonable or dumb? Related links: How can I get the order of an element attribute list using Python xml.sax? Preserve order of attributes when modifying with minidom

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How can I make this method more Scalalicious

- by Neil Chambers

I have a function that calculates the left and right node values for some collection of treeNodes given a simple node.id, node.parentId association. It's very simple and works well enough...but, well, I am wondering if there is a more idiomatic approach. Specifically is there a way to track the left/right values without using some externally tracked value but still keep the tasty recursion. /* * A tree node */ case class TreeNode(val id:String, val parentId: String){ var left: Int = 0 var right: Int = 0 } /* * a method to compute the left/right node values */ def walktree(node: TreeNode) = { /* * increment state for the inner function */ var c = 0 /* * A method to set the increment state */ def increment = { c+=1; c } // poo /* * the tasty inner method * treeNodes is a List[TreeNode] */ def walk(node: TreeNode): Unit = { node.left = increment /* * recurse on all direct descendants */ treeNodes filter( _.parentId == node.id) foreach (walk(_)) node.right = increment } walk(node) } walktree(someRootNode) Edit - The list of nodes is taken from a database. Pulling the nodes into a proper tree would take too much time. I am pulling a flat list into memory and all I have is an association via node id's as pertains to parents and children. Adding left/right node values allows me to get a snapshop of all children (and childrens children) with a single SQL query. The calculation needs to run very quickly in order to maintain data integrity should parent-child associations change (which they do very frequently). In addition to using the awesome Scala collections I've also boosted speed by using parallel processing for some pre/post filtering on the tree nodes. I wanted to find a more idiomatic way of tracking the left/right node values. After looking at the answers listed I have settled on this synthesised version: def walktree(node: TreeNode) = { def walk(node: TreeNode, counter: Int): Int = { node.left = counter node.right = treeNodes .filter( _.parentId == node.id) .foldLeft(counter+1) { (counter, curnode) => walk(curnode, counter) + 1 } node.right } walk(node,1) }

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Automatically add links to class source files under a specified directory of an another project in V

- by Binary255

I want to share some class source files between two projects in Visual Studio 2008. I can't create a project for the common parts and reference it (see my comment if you are curious to why). I've managed to share some source files, but it could be a lot more neat. I've created a test solution called Commonality. The Solution Explorer of the Commonality solution which contains project One and Two: What I like: All class files under the Common folder of project One are automatically added to project Two by linking. It's mostly the same as if I would have chosen Add / Existing Item... : Add As Link on each new class source file. It's clear that these files have been linked in. The shortcut arrow symbol is marking each file icon. What I do not like: The file and folder tree structure under Common of project One isn't included. It's all flat. The linked source files are shown under the project root of project Two. It would look much less cluttered if they were located under Common like in project One. The file tree structure of the Commonality solution which contains project One and Two: $ tree /F /A Folder PATH listing for volume Cystem Volume serial number is 0713370 1337:F6A4 C:. | Commonality.sln | +---One | | One.cs | | One.csproj | | | +---bin | | \---Debug | | One.vshost.exe | | One.vshost.exe.manifest | | | +---Common | | | Common.cs | | | CommonTwo.cs | | | | | \---SubCommon | | CommonThree.cs | | | +---obj | | \---Debug | | +---Refactor | | \---TempPE | \---Properties | AssemblyInfo.cs | \---Two | Two.cs | Two.csproj | Two.csproj.user | Two.csproj~ | +---bin | \---Debug +---obj | \---Debug | +---Refactor | \---TempPE \---Properties AssemblyInfo.cs And the relevant part of project Two's project file Two.csproj: <ItemGroup> <Compile Include="..\One\Common\**\*.cs"> </Compile> <Compile Include="Two.cs" /> <Compile Include="Properties\AssemblyInfo.cs" /> </ItemGroup> How do I address what I do not like, while keeping what I like?

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Brackets matching using BIT

- by amit.codename13

edit: I was trying to solve a spoj problem. Here is the link to the problem : http://spoj.pl/problems/BRCKTS I can think of two possible data structures for solving the problem one using segment tree and the other using a BIT. I have already implemented the solution using a segment tree. I have read about BIT but i can't figure out how to do a particular thing with it(which i have mentioned below) I am trying to check if brackets are balanced in a given string containing only ('s or )'s. I am using a BIT(Binary indexed tree) for solving the problem. The procedure i am following is as follows: I am taking an array of size equal to the number of characters in the string. I am assigning -1 for ) and 1 for ( to the corresponding array elements. Brackets are balanced in the string only if the following two conditions are true. The cumulative sum of the whole array is zero. Minimum cumulative sum is non negative. i.e the minimum of cumulative sums of all the prefixes of the array is non-negative. Checking condition 1 using a BIT is trivial. I am facing problem in checking condition 2.

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Good Starting Points for Optimizing Database Calls in Ruby on Rails?

- by viatropos

I have a menu in Rails which grabs a nested tree of Post models, each which have a Slug model associated via a polymorphic association (using the friendly_id gem for slugs and awesome_nested_set for the tree). The database output in development looks like this (here's the full gist): SQL (0.4ms) SELECT COUNT(*) AS count_id FROM "posts" WHERE ("posts".parent_id = 39) CACHE (0.0ms) SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 13) LIMIT 1 CACHE (0.0ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 13 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 Slug Load (0.4ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 40 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 SQL (0.3ms) SELECT COUNT(*) AS count_id FROM "posts" WHERE ("posts".parent_id = 40) CACHE (0.0ms) SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 13) LIMIT 1 CACHE (0.0ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 13 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 Slug Load (0.4ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 41 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 ... Rendered shared/_menu.html.haml (907.6ms) What are some quick things I should always do to optimize this from the start (easy things)? Some things I'm thinking now are: Can Rails 3 eager load the whole Post tree + associated Slugs in one DB call? Can I do that easily with named scopes or custom SQL? What is best practice in this situation? Not really thinking about memcached in this situation as that can be applied to much more than just this.

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Enabling new admin action(button sales_order/view) in ACL

- by latvian

Hi, We created new action similar to 'hold', 'ship' and others in the 'sales_order/view' admin section that can be triggered by clicking at the button. Afterward, we added our new action to the ACL with the following code in config.xml: <acl> <resources> <admin> <children> <sales> <children> <order> <children> <actions translate="title"> <title>Actions</title> <children> <shipNew translate="title"><title>Ship Ups</title></shipNew> </children> </actions> </children> <sort_order>10</sort_order> </order> </children> </sales> </children> </admin> </resources> </acl> ACL functionality works, however, in the 'Resources Tree'(System/Permissions/Roles/Role Resources) our new action does never show up as selected(checked) even thou it is allowed for particular Role. I can see that from table 'admin_rule' with resource id for our new action that it is allowed, so it needs to be selected, but it is not. When trying to solve this issue i looked into the template(permissions/rolesedit.phtml) and I found that the 'resource tree' is draw with Javascript...thats where i got stock due to my limited knowledge in Javascript. Why the resource tree does not display our new ACL entry correctly, that is the check box is never checked? Thank You for helping margots

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Can LINQ expression classes implement the observer pattern instead of deferred execution?

- by Tormod

Hi. We have issues within an application using a state machine. The application is implemented as a windows service and is iteration based (it "foreaches" itself through everything) and there are myriads of instances being processed by the state machine. As I'm reading the MEAP version of Jon Skeets book "C# in Depth, 2nd ed", I'm wondering if I can change the whole thing to use linq expression instances so that guards and conditions are represented using expression trees. We are building many applications on this state machine engine and would probably greatly benefit from the new Expression tree visualizer in VS 2010 Now, simple example. If I have an expression tree where there is an OR Expression condition with two sub nodes, is there any way that these can implement the observer pattern so that the expression tree becomes event driven? If a condition change, it should notify its parent node (the OR node). Since the OR node then changes from "false" to "true", then it should notify ITS parent and so on. I love the declarative model of expression trees, but the deferred execution model works in opposite direction of the control flow if you want event based "live" conditions. Am I off on a wild goose chase here? Or is there some concept in the BCL that may help me achieve this?

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parse xml with elementtree, custom sorting

- by microspace

I want to parse xml file in utf-8 and sort it by some field. Soring is made by custom alphabet (s1 from sourcecode). History of question is here: sorting of list containing utf-8 charachters. I've found how to sort xml here. Sorting work correctly, the problem is with elementtree, I must admit that it doesn't work on python3 Here is source code: #!/usr/bin/env python # -*- coding: utf-8 -*- #import xml.etree.ElementTree as ET # Python 2.5 import elementtree.ElementTree as ET s1='aáàAâÂbBcCçÇdDeéEfFgGgGhHiIîÎíiiIjJkKlLmMnNóoOöÖpPqQrRsSsStTuUûúÛüÜvVwWxXyYzZ' s2='11111122334455666aabbccddeeeeeeffgghhiijjkklllllmmnnooppqqrrsssssttuuvvwwxxyy' trans = str.maketrans(s1, s2) def unikey(seq): return seq[0].translate(trans) tree = ET.parse("tosort.xml") container = tree.find("entries") data = [] for elem in container: keyd = elem.findtext("k") data.append((keyd, elem)) print (data) data.sort(key=unikey) print (data) container[:] = [item[-1] for item in data] tree.write("sorted.xml", encoding="utf-8") Here are instructions to import elementtree module. When I import module this way :import xml.etree.ElementTree as ET, I get a message: Traceback (most recent call last): File "pcs.py", line 19, in <module> container[:] = [item[-1] for item in data] File "/usr/lib/python3.1/xml/etree/ElementTree.py", line 210, in __setitem__ assert iselement(element) AssertionError When I use this method to import: import elementtree.ElementTree as ET, I get this message: Traceback (most recent call last): File "pcs.py", line 4, in <module> import elementtree.ElementTree as ET File "/usr/local/lib/python3.1/dist-packages/elementtree/ElementTree.py", line 794, in <module> _escape = re.compile(eval(r'u"[&<>\"\u0080-\uffff]+"')) File "<string>", line 1 u"[&<>\"\u0080-\uffff]+" ^ SyntaxError: invalid syntax I use Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10). In python2.6 elementtree work without a problem. Content of tosort.xml: <xdxf> <entries> <ar><k>zaaaa</k>definition1</ar> <ar><k>saaaa</k>definition2</ar> ... ... </entries> </xdxf>

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How to create an AST with ANTLR from a hierarchical key-value syntax

- by Brabster

I've been looking at parsing a key-value data format with ANTLR. Pretty straightforward, but the keys represent a hierarchy. A simplified example of my input syntax: /a/b/c=2 /a/b/d/e=3 /a/b/d/f=4 In my mind, this represents a tree structured as follows: (a (b (= c 2) (d (= e 3) (= f 4)))) The nearest I can get is to use the following grammar: /* Parser Rules */ start: (component NEWLINE?)* EOF -> (component)*; component: FORWARD_SLASH ALPHA_STRING component -> ^(ALPHA_STRING component) | FORWARD_SLASH ALPHA_STRING EQUALS value -> ^(EQUALS ALPHA_STRING value); value: ALPHA_STRING; /* Lexer Rules */ NEWLINE : '\r'? '\n'; ALPHA_STRING : ('a'..'z'|'A'..'Z'|'0'..'9')+; EQUALS : '='; FORWARD_SLASH : '/'; Which produces: (a (b (= c 2))) (a (b (d (= e 3)))) (a (b (d (= f 4)))) I'm not sure whether I'm asking too much from a generic tool such as ANTLR here, and this is as close I can get with this approach. That is, from here I consume the parts of the tree and create the data structure I want by hand. So - can I produce the tree structure I want directly from a grammar? If so, how? If not, why not - is it a technical limitation in ANTLR or is it something more CS-y to do with the type of language involved?

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How to highlight the new created file in JTree

- by newbie123

I want to make it like when I click a button, it will create a new file. Then the jTree will highlight the new file. Below are my code. Currently I create new file, i will show the new file but no highlight the file. class FileTreeModel implements TreeModel { private FileNode root; public FileTreeModel(String directory) { root = new FileNode(directory); } public Object getRoot() { return root; } public Object getChild(Object parent, int index) { FileNode parentNode = (FileNode) parent; return new FileNode(parentNode, parentNode.listFiles()[index].getName()); } public int getChildCount(Object parent) { FileNode parentNode = (FileNode) parent; if (parent == null || !parentNode.isDirectory() || parentNode.listFiles() == null) { return 0; } return parentNode.listFiles().length; } public boolean isLeaf(Object node) { return (getChildCount(node) == 0); } public int getIndexOfChild(Object parent, Object child) { FileNode parentNode = (FileNode) parent; FileNode childNode = (FileNode) child; return Arrays.asList(parentNode.list()).indexOf(childNode.getName()); } public void valueForPathChanged(TreePath path, Object newValue) { } public void addTreeModelListener(TreeModelListener l) { } public void removeTreeModelListener(TreeModelListener l) { } } class FileNode extends java.io.File { public FileNode(String directory) { super(directory); } public FileNode(FileNode parent, String child) { super(parent, child); } @Override public String toString() { return getName(); } } jTree = new JTree(); jTree.setBounds(new Rectangle(164, 66, 180, 421)); jTree.setBackground(SystemColor.inactiveCaptionBorder); jTree.setBorder(BorderFactory.createTitledBorder(null, "", TitledBorder.LEADING, TitledBorder.TOP, new Font("Arial", Font.BOLD, 12), new Color(0, 0, 0))); FileTreeModel model = new FileTreeModel(root); jTree.setRootVisible(false); jTree.setModel(model); expandAll(jTree); public void expandAll(JTree tree) { int row = 0; while (row < tree.getRowCount()) { tree.expandRow(row); row++; } }

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Is it a good idea to use MySQL and Neo4j together?

- by Sanoj

I will make an application with a lot of similar items (millions), and I would like to store them in a MySQL database, because I would like to do a lot of statistics and search on specific values for specific columns. But at the same time, I will store relations between all the items, that are related in many connected binary-tree-like structures (transitive closure), and relation databases are not good at that kind of structures, so I would like to store all relations in Neo4j which have good performance for this kind of data. My plan is to have all data except the relations in the MySQL database and all relations with item_id stored in the Neo4j database. When I want to lookup a tree, I first search the Neo4j for all the item_id:s in the tree, then I search the MySQL-database for all the specified items in a query that would look like: SELECT * FROM items WHERE item_id = 45 OR item_id = 345435 OR item_id = 343 OR item_id = 78 OR item_id = 4522 OR item_id = 676 OR item_id = 443 OR item_id = 4255 OR item_id = 4345 Is this a good idea, or am I very wrong? I haven't used graph-databases before. Are there any better approaches to my problem? How would the MySQL-query perform in this case?

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How to find the closest descendants (hat matches a selector) with jQuery?

- by powerboy

We can use closest(selector) to find the first ancestor element that matches the selector. It travels up the DOM tree until it finds a match for the selector. But what if I want to travels down the DOM tree until it finds a match for the selector? Is there any jQuery function for doing this? Give an example. For the DOM tree below, <div id="main"> <div> <ul> <li> <ul> </ul> </li> </ul> <ul> </ul> </div> </div> how to do something like $('#main').closestDescendants('ul')?

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Generic version control strategy for select table data within a heavily normalized database

- by leppie

Hi Sorry for the long winded title, but the requirement/problem is rather specific. With reference to the following sample (but very simplified) structure (in psuedo SQL), I hope to explain it a bit better. TABLE StructureName { Id GUID PK, Name varchar(50) NOT NULL } TABLE Structure { Id GUID PK, ParentId GUID (FK to Structure), NameId GUID (FK to StructureName) NOT NULL } TABLE Something { Id GUID PK, RootStructureId GUID (FK to Structure) NOT NULL } As one can see, Structure is a simple tree structure (not worried about ordering of children for the problem). StructureName is a simplification of a translation system. Finally 'Something' is simply something referencing the tree's root structure. This is just one of many tables that need to be versioned, but this one serves as a good example for most cases. There is a requirement to version to any changes to the name and/or the tree 'layout' of the Structure table. Previous versions should always be available. There seems to be a few possibilities to tackle this issue, like copying the entire structure, but most approaches causes one to 'loose' referential integrity. Example if one followed this approach, one would have to make a duplicate of the 'Something' record, given that the root structure will be a new record, and have a new ID. Other avenues of possible solutions are looking into how Wiki's handle this or go a lot further and look how proper version control systems work. Currently, I feel a bit clueless how to proceed on this in a generic way. Any ideas will be greatly appreciated. Thanks leppie

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IntelliJ Doesn't Notice Changes in Interface

- by yar

[I've decided to give IntelliJ another go (to replace Eclipse), since its Groovy support is supposed to be the best. But back to Java...] I have an Interface that defines a constant public static final int CHANNEL_IN = 1; and about 20 classes in my Module that implement that interface. I've decided that this constant was a bad idea so I did what I do in Eclipse: I deleted the entire line. This should cause the Project tree to light up like a Christmas tree and all classes that implement that interface and use that constant to break. Instead, this is not happening. If I don't actually double-click on the relevant classes -- which I find using grep -- the module even builds correctly (using Build - Make Module). If I double-click on a relevant class, the error is shown both in the Project Tree and in the Editor. I am not able to replicate this behavior in small tests, but in large modules it works (incorrectly) this way. Is there some relevant setting in IntelliJ for this?

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How do I controll clipping with non-opaque graphics-item's in Qt?

- by JJacobsson

I have a bunch of QGraphicsSvgItem's in a QGraphicsScene that are drawn connected by QGraphicsLineItem's. This show's a graph of a tree-structure. What I want to do is provide a feature where everything but a selected sub-tree becomes transparent. A kind of "highlight this sub-tree" feature. That part was easy, but the results are ugly because now the lines can be seen through the semi-transparent svg's. I am looking for some way to still clip other QGraphicsItem's in the scene to the svg item's, giving the effect that the svg's are semi-transparent windows to the background. I know this code does not use svg's but I figure you can replace that yourself if you are so inclined. int main(int argc, char *argv[]) { QApplication app(argc, argv); QGraphicsScene scene; for( int i = 0; i < 10; ++i ) { QGraphicsLineItem* line = new QGraphicsLineItem; line->setLine( i * 25.0 + 1.0, 0, i * 25.0 + 23.0, 0 ); scene.addItem( line ); } for( int i = 0; i < 11; ++i ) { QGraphicsEllipseItem* ellipse = new QGraphicsEllipseItem; ellipse->setRect( (i * 25.0) - 9.0, -9.0, 18.0, 18.0f ); ellipse->setBrush( QBrush( Qt::green, Qt::SolidPattern ) ); ellipse->setOpacity( 0.5 ); scene.addItem( ellipse ); } QGraphicsView view( &scene ); view.show(); return app.exec(); } I would like the line's to not be seen behind the circle's. I have tried fiddling with the depth-buffer and the stencil buffer using opengl rendering to no avail. How do I get the QGraphicsSvgItem's (or QGraphicsEllipseItem's in the example code) to still clip the lines even though they are semi-transparent?

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TreeView Control Problem

- by ProgNet

Hi all, I have a public folder on the server that contains recursively nested sub folders. In the various Leaf folders contains Images. I wanted to create a server side file browser that will display the Images to the user. I am using the ASP.NET TreeView Control. I create the tree nodes using PopulateOnDemand. If the user click on a leaf directory I want the images in that folder to be displayed in a DataList Control. The problem is that when I click on a sub tree node (after I expanded it parent node) All the expanded sub tree disappears and only the parent node is showed with no + sign next to it !! ( I have set the TreeView's PopulateNodesFromClient property to true ) Can someone tell me what is the problem ?? Thanks Here is the code : <asp:TreeView ID="TreeView1" runat="server" AutoGenerateDataBindings="False" onselectednodechanged="TreeView1_SelectedNodeChanged" ontreenodepopulate="TreeView1_TreeNodePopulate"> </asp:TreeView> protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { string path = Server.MapPath("."); PopulateTopNodes(path); } } private void PopulateTopNodes(string pathToRootFolder) { DirectoryInfo dirInfo = new DirectoryInfo(pathToRootFolder); DirectoryInfo[] dirs = dirInfo.GetDirectories(); foreach (DirectoryInfo dir in dirs) { TreeNode folderNode = new TreeNode(dir.Name,dir.FullName); if (dir.GetDirectories().Length > 0) { folderNode.PopulateOnDemand = true; folderNode.Collapse(); } TreeView1.Nodes.Add(folderNode); } } protected void TreeView1_TreeNodePopulate(object sender, TreeNodeEventArgs e) { if (IsCallback == true) { if (e.Node.ChildNodes.Count == 0) { LoadChildNode(e.Node); } } } private void LoadChildNode(TreeNode treeNode) { DirectoryInfo dirInfo = new DirectoryInfo(treeNode.Value); DirectoryInfo[] dirs = dirInfo.GetDirectories(); foreach (DirectoryInfo dir in dirs) { TreeNode folderNode = new TreeNode(dir.Name, dir.FullName); if(dir.GetDirectories().Length>0){ folderNode.PopulateOnDemand = true; folderNode.Collapse(); } treeNode.ChildNodes.Add(folderNode); } } protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e) { // Retrieve the images here }

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How do I add the go language to gitg's list of viewable sources?

- by Hotei

Hoping a 'git' guru will help out here. I am just beginning to "git" for the first time and have (among other things :-) ) git and gitg installed from Ubuntu 10.4 / AMD64 distribution (ie. maybe not 'latest' version but not ancient). I am trying to look at the go code I've committed via gitg and in the "tree tab" it says :Cannot display file content as text. However, the "details tab" shows the diffs of the same file just fine. I know gitg's "tree tab" is working because I can use the tree view on *.c / *.html / *.txt etc just fine. Is there a way to tweak gitg into understanding that "*.go" is just text? A little more context: Installed gitg version is 0.0.5 - ie a version behind latest - 0.0.6 - source of which I am looking thru now. I do have a working /usr/share/gtksourceview-2.0/language-specs/ go.lang. It works just fine as highlighter in gedit. It appears that gitg may require displayable files to have a mime type of "text/plain", so I added that to go.lang No joy. gitg still fails on *.go I'm relatively sure the fix is simple, just don't know where to look.

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How to find the closest descendants (that matches a selector) with jQuery?

- by powerboy

We can use closest(selector) to find the first ancestor element that matches the selector. It travels up the DOM tree until it finds a match for the selector. But what if I want to travels down the DOM tree until it finds a match for the selector? Is there any jQuery function for doing this? Or do I need to implement this using breadth-first search? Give an example. For the DOM tree below, <div id="main"> <div> <ul> <li> <ul> </ul> </li> </ul> <ul> </ul> </div> </div> how to do something like $('#main').closestDescendants('ul')?

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Java Graphics not displaying on successive function calls, why?

- by primehunter326

Hi, I'm making a visualization for a BST implementation (I posted another question about it the other day). I've created a GUI which displays the viewing area and buttons. I've added code to the BST implementation to recursively traverse the tree, the function takes in coordinates along with the Graphics object which are initially passed in by the main GUI class. My idea was that I'd just have this function re-draw the tree after every update (add, delete, etc...), drawing a rectangle over everything first to "refresh" the viewing area. This also means I could alter the BST implementation (i.e by adding a balance operation) and it wouldn't affect the visualization. The issue I'm having is that the draw function only works the first time it is called, after that it doesn't display anything. I guess I don't fully understand how the Graphics object works since it doesn't behave the way I'd expect it to when getting passed/called from different functions. I know the getGraphics function has something to do with it. Relevant code: private void draw(){ Graphics g = vPanel.getGraphics(); tree.drawTree(g,ORIGIN,ORIGIN); } vPanel is what I'm drawing on private void drawTree(Graphics g, BinaryNode<AnyType> n, int x, int y){ if( n != null ){ drawTree(g, n.left, x-10,y+10 ); if(n.selected){ g.setColor(Color.blue); } else{ g.setColor(Color.gray); } g.fillOval(x,y,20,20); g.setColor(Color.black); g.drawString(n.element.toString(),x,y); drawTree(g,n.right, x+10,y+10); } } It is passed the root node when it is called by the public function. Do I have to have: Graphics g = vPanel.getGraphics(); ...within the drawTree function? This doesn't make sense!! Thanks for your help.

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A Question about dereferencing pointer to incomplete type In C programming

- by user552279

Hi, can you explain this error for me? Blockquote /////////////////////////////// In my A.h file: struct TreeNode; struct TreeHead; typedef struct TreeNode * Node; typedef struct TreeHead * Head; /////////////////////////////// In my A.c file: struct TreeNode { char* theData; Node Left; Node Right; } ; struct TreeHead{ int counter; char type; Node Root; }; Head Initialisation() { Head treeHead; treeHead = malloc(sizeof (struct TreeHead)); treeHead-Root = malloc(sizeof (struct TreeNode)); return treeHead; } /////////////////////////////// In my Main.c file: Head head; Node tree; int choose =5; head = Initialisation(); (head-Root) = tree; //When compiling, this line has an error: error: dereferencing pointer to incomplete type Blockquote haed-Root will return a Node pointer, tree is also a Node pointer. So why error is dereferencing pointer to "incomplete" type?

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How to get results efficiently out of an Octree/Quadtree?

- by Reveazure

I am working on a piece of 3D software that has sometimes has to perform intersections between massive numbers of curves (sometimes ~100,000). The most natural way to do this is to do an N^2 bounding box check, and then those curves whose bounding boxes overlap get intersected. I heard good things about octrees, so I decided to try implementing one to see if I would get improved performance. Here's my design: Each octree node is implemented as a class with a list of subnodes and an ordered list of object indices. When an object is being added, it's added to the lowest node that entirely contains the object, or some of that node's children if the object doesn't fill all of the children. Now, what I want to do is retrieve all objects that share a tree node with a given object. To do this, I traverse all tree nodes, and if they contain the given index, I add all of their other indices to an ordered list. This is efficient because the indices within each node are already ordered, so finding out if each index is already in the list is fast. However, the list ends up having to be resized, and this takes up most of the time in the algorithm. So what I need is some kind of tree-like data structure that will allow me to efficiently add ordered data, and also be efficient in memory. Any suggestions?

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The perverse hangman problem

- by Shalmanese

Perverse Hangman is a game played much like regular Hangman with one important difference: The winning word is determined dynamically by the house depending on what letters have been guessed. For example, say you have the board _ A I L and 12 remaining guesses. Because there are 13 different words ending in AIL (bail, fail, hail, jail, kail, mail, nail, pail, rail, sail, tail, vail, wail) the house is guaranteed to win because no matter what 12 letters you guess, the house will claim the chosen word was the one you didn't guess. However, if the board was _ I L M, you have cornered the house as FILM is the only word that ends in ILM. The challenge is: Given a dictionary, a word length & the number of allowed guesses, come up with an algorithm that either: a) proves that the player always wins by outputting a decision tree for the player that corners the house no matter what b) proves the house always wins by outputting a decision tree for the house that allows the house to escape no matter what. As a toy example, consider the dictionary: bat bar car If you are allowed 3 wrong guesses, the player wins with the following tree: Guess B NO -> Guess C, Guess A, Guess R, WIN YES-> Guess T NO -> Guess A, Guess R, WIN YES-> Guess A, WIN

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