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  • asp.net + How to create custom multi-templated tree databound control?

    - by ParagM
    I dont want to use asp.net's TreeView control. I want to create a custom template databound control with multi template support like - <asp:MtNavigationControl> <ItemTemplate> ... ... </ItemTemplate> <SelectedItemTemplate> ... ... </SelectedItemTemplate> <ParentItemTemplate> ... ... </ParentSelectedItemTemplate> <SelectedParentItemTemplate> ... ... </SelectedParentSelectedItemTemplate> </asp:MtNavigationControl> My data is like - class Employee { string EmployeeName List<Employee> Employees } Does anyone know how to accomplish it? Please help !!!

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  • LaTeX limitation?

    - by Jayen
    Hi, I've hit an annoying problem in LaTeX. I've got a tex file of about 1000 lines. I've already got a few figures, but when I try to add another figure, It barfs with: ! Undefined control sequence. <argument> ... \sf@size \z@ \selectfont \@currbox l.937 \begin{figure}[t] If I move the figure to other parts of the file, I can get similar errors on different lines: ! Undefined control sequence. <argument> ... \sf@size \z@ \selectfont \@currbox l.657 \paragraph {A Centering Algorithm} If I comment out the figure, all is ok. %\begin{figure}[t] % \caption{Example decision tree, from Reiter and Dale [2000]} % \label{fig:relation-decision-tree} % \centering % \includegraphics[keepaspectratio=true]{./relation-decision-tree.eps} %\end{figure} If I keep just the begin and end like: \begin{figure}%[t] % \caption{Example decision tree, from Reiter and Dale [2000]} % \label{fig:relation-decision-tree} % \centering % \includegraphics[keepaspectratio=true]{./relation-decision-tree.eps} \end{figure} I get: ! Undefined control sequence. <argument> ... \sf@size \z@ \selectfont \@currbox l.942 \end {figure} At first, I thought maybe LaTeX has hit some limit, and I tried playing with the ulimits, but that didn't help. Any ideas? i've got other figures with graphics already. my preamble looks like: \documentclass[acmcsur,acmnow]{acmtrans2n} \usepackage{array} \usepackage{lastpage} \usepackage{pict2e} \usepackage{amsmath} \usepackage{varioref} \usepackage{epsfig} \usepackage{graphics} \usepackage{qtree} \usepackage{rotating} \usepackage{tree-dvips} \usepackage{mdwlist} \makecompactlist{quote*}{quote} \usepackage{verbatim} \usepackage{ulem}

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  • JTree events seem misordered

    - by MeBigFatGuy
    It appears to me that tree selection events should happen after focus events, but this doesn't seem to be the case. Assume you have a JTree and a JTextField, where the JTextField is populated by what is selected in the tree. When the user changes the text field, on focus lost, you update the tree from the text field. however, the tree selection is changed before the focus is lost on the text field. this is incorrect, right? Any ideas? Here is some sample code: import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class Focus extends JFrame { public static void main(String[] args) { Focus f = new Focus(); f.setLocationRelativeTo(null); f.setVisible(true); } public Focus() { Container cp = getContentPane(); cp.setLayout(new BorderLayout()); final JTextArea ta = new JTextArea(5, 10); cp.add(new JScrollPane(ta), BorderLayout.SOUTH); JSplitPane sp = new JSplitPane(); cp.add(sp, BorderLayout.CENTER); JTree t = new JTree(); t.addTreeSelectionListener(new TreeSelectionListener() { public void valueChanged(TreeSelectionEvent tse) { ta.append("Tree Selection changed\n"); } }); t.addFocusListener(new FocusListener() { public void focusGained(FocusEvent fe) { ta.append("Tree focus gained\n"); } public void focusLost(FocusEvent fe) { ta.append("Tree focus lost\n"); } }); sp.setLeftComponent(new JScrollPane(t)); JTextField f = new JTextField(10); sp.setRightComponent(f); pack(); f.addFocusListener(new FocusListener() { public void focusGained(FocusEvent fe) { ta.append("Text field focus gained\n"); } public void focusLost(FocusEvent fe) { ta.append("Text field focus lost\n"); } }); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }

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  • DIY intellisense on XPath - design approach? (WinForms app)

    - by Cheeso
    I read the DIY Intellisense article on code project, which was referenced from the Mimic Intellisense? question here on SO. I wanna do something similar, DIY intellisense, but for XPath not C#. The design approach used there makes sense to me: maintain a tree of terms, and when the "completion character" is pressed, in the case of C#, a dot, pop up the list of possible completions in a textfield. Then allow the user to select a term from the textfield either through typing, arrow keys, or double-click. How would you apply this to XPath autocompletion? should there be an autocomplete key? In XPath there is no obvious separator key like "dot" in C#. should the popup be triggered explicitly in some other way, let's say ctrl-. ? or should the parser try to autocomplete continuously? If I do the autocomplete continuously, how to scale it properly? There are 93 xpath functions, not counting overloads. I certainly don't want to popup a list of 93 choices. How do I decide when I've narrowed it enough to offer a useful lsit of possible completions? How to populate the tree of possible completions? For C#, it's easy: walk the type space via reflection. At a first level, the "syntax tree" for C# seems like a single tree, and the list of completions at any point depends on the graph of nodes you've traversed to that point. Typing System.Console. traverses to a certain node in that tree, and the list of completions is the set of child nodes available at that node in the tree. On the other hand, the xpath syntax seems like it is a "flatter" tree - function names, axis names, literals. Does this make sense? what have I not considered?

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  • PHP: Recursively get children of parent

    - by Nic Hubbard
    I have a function which gets the ids of all children of a parent from my DB. So, if I looked up id 7, it might return an array with 5, 6 and 10. What I then want to do, is recursively find the children of those returned ids, and so on, to the final depth of the children. I have tried to write a function to do this, but I am getting confused about recursion. function getChildren($parent_id) { $tree = Array(); $tree_string; if (!empty($parent_id)) { // getOneLevel() returns a one-dimentional array of child ids $tree = $this->getOneLevel($parent_id); foreach ($tree as $key => $val) { $ids = $this->getChildren($val); array_push($tree, $ids); //$tree[] = $this->getChildren($val); $tree_string .= implode(',', $tree); } return $tree_string; } else { return $tree; } }//end getChildren() After the function is run, I would like it to return a one-dimentional array of all the child ids that were found.

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  • Swing: what to do when a JTree update takes too long and freezes other GUI elements?

    - by java.is.for.desktop
    Hello, everyone! I know that GUI code in Java Swing must be put inside SwingUtilities.invokeAndWait or SwingUtilities.invokeLater. This way threading works fine. Sadly, in my situation, the GUI update it that thing which takes much longer than background thread(s). More specific: I update a JTree with about just 400 entries, nesting depth is maximum 4, so should be nothing scary, right? But it takes sometimes one second! I need to ensure that the user is able to type in a JTextPane without delays. Well, guess what, the slow JTree updates do cause delays for JTextPane during input. It refreshes only as soon as the tree gets updated. I am using Netbeans and know empirically that a Java app can update lots of information without freezing the rest of the UI. How can it be done? NOTE 1: All those DefaultMutableTreeNodes are prepared outside the invokeAndWait. NOTE 2: When I replace invokeAndWait with invokeLater the tree doesn't get updated. NOTE 3: Fond out that recursive tree expansion takes far the most time. NOTE 4: I'm using custom tree cell renderer, will try without and report. NOTE 4a: My tree cell renderer uses a map to cache and reuse created JTextComponents, depending on tree node (as a key). CLUE 1: Wow! Without setting custom cell renderer it's 10 times faster. I think, I'll need few good tutorials on writing custom tree cell renderers.

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  • Monads and custom traversal functions in Haskell

    - by Bill
    Given the following simple BST definition: data Tree x = Empty | Leaf x | Node x (Tree x) (Tree x) deriving (Show, Eq) inOrder :: Tree x -> [x] inOrder Empty = [] inOrder (Leaf x) = [x] inOrder (Node root left right) = inOrder left ++ [root] ++ inOrder right I'd like to write an in-order function that can have side effects. I achieved that with: inOrderM :: (Show x, Monad m) => (x -> m a) -> Tree x -> m () inOrderM f (Empty) = return () inOrderM f (Leaf y) = f y >> return () inOrderM f (Node root left right) = inOrderM f left >> f root >> inOrderM f right -- print tree in order to stdout inOrderM print tree This works fine, but it seems repetitive - the same logic is already present in inOrder and my experience with Haskell leads me to believe that I'm probably doing something wrong if I'm writing a similar thing twice. Is there any way that I can write a single function inOrder that can take either pure or monadic functions?

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  • Random forests for short texts

    - by Jasie
    Hi all, I've been reading about Random Forests (1,2) because I think it'd be really cool to be able to classify a set of 1,000 sentences into pre-defined categories. I'm wondering if someone can explain to me the algorithm better, I think the papers are a bit dense. Here's the gist from 1: Overview We assume that the user knows about the construction of single classification trees. Random Forests grows many classification trees. To classify a new object from an input vector, put the input vector down each of the trees in the forest. Each tree gives a classification, and we say the tree "votes" for that class. The forest chooses the classification having the most votes (over all the trees in the forest). Each tree is grown as follows: If the number of cases in the training set is N, sample N cases at random - but with replacement, from the original data. This sample will be the training set for growing the tree. If there are M input variables, a number m « M is specified such that at each node, m variables are selected at random out of the M and the best split on these m is used to split the node. The value of m is held constant during the forest growing. Each tree is grown to the largest extent possible. There is no pruning. So, does this look right? I'd have N = 1,000 training cases (sentences), M = 100 variables (let's say, there are only 100 unique words across all sentences), so the input vector is a bit vector of length 100 corresponding to each word. I randomly sample N = 1000 cases at random (with replacement) to build trees from. I pick some small number of input variables m « M, let's say 10, to build a tree off of. Do I build tree nodes randomly, using all m input variables? How many classification trees do I build? Thanks for the help!

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  • B- trees, B+ trees difference

    - by dta
    In a B- tree you can store both keys and data in the internal/leaf nodes. But in a B+ tree you have to store the data in the leaf nodes only. Is there any advantage of doing the above in a B+ tree? Why not use B- trees instead of B+ trees everywhere? As intuitively they seem much faster. I mean why do you need to replicate the key(data) in a B+ tree?

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  • Is it possible to create a C++ factory system that can create an instance of any "registered" object

    - by chrensli
    Hello, I've spent my entire day researching this topic, so it is with some scattered knowledge on the topic that i come to you with this inquiry. Please allow me to describe what I am attempting to accomplish, and maybe you can either suggest a solution to the immediate question, or another way to tackle the problem entirely. I am trying to mimic something related to how XAML files work in WPF, where you are essentially instantiating an object tree from an XML definition. If this is incorrect, please inform. This issue is otherwise unrelated to WPF, C#, or anything managed - I solely mention it because it is a similar concept.. So, I've created an XML parser class already, and generated a node tree based on ObjectNode objects. ObjectNode objects hold a string value called type, and they have an std::vector of child ObjectNode objects. The next step is to instantiate a tree of objects based on the data in the ObjectNode tree. This intermediate ObjectNode tree is needed because the same ObjectNode tree might be instantiated multiple times or delayed as needed. The tree of objects that is being created is such that the nodes in the tree are descendants of a common base class, which for now we can refer to as MyBase. Leaf nodes can be of any type, not necessarily derived from MyBase. To make this more challenging, I will not know what types of MyBase derived objects might be involved, so I need to allow for new types to be registered with the factory. I am aware of boost's factory. Their docs have an interesting little design paragraph on this page: o We may want a factory that takes some arguments that are forwarded to the constructor, o we will probably want to use smart pointers, o we may want several member functions to create different kinds of objects, o we might not necessarily need a polymorphic base class for the objects, o as we will see, we do not need a factory base class at all, o we might want to just call the constructor - without #new# to create an object on the stack, and o finally we might want to use customized memory management. I might not be understanding this all correctly, but that seems to state that what I'm trying to do can be accomplished with boost's factory. But all the examples I've located, seem to describe factories where all objects are derived from a base type. Any guidance on this would be greatly appreciated. Thanks for your time!

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  • Passing around an ElementTree

    - by PulpFiction
    Hello. In my program, I need to make use of an ElementTree object in various functions in my program. More specifically, I am doing this: tree = etree.parse('somefile.xml') I am passing this tree around in my program. I was wondering whether this is a good approach, or can I do this: Create a global tree (I come from a C++ background and I know global is bad) Create the tree again wherever required. Or is my approach ok?

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  • How can I merge the gnome clipboard and the X selection?

    - by TREE
    I'm constantly frustrated by the two separate clipboards in X/Gnome. I'm constantly doing things like control-C to copy, and then middle-click to paste, and getting the wrong data. Or select something, then go where I want to paste it, and selecting what I want to paste over, only to lose my first selection! Is there any way to merge these two clipboards?

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  • How is Core Data detecting the conflicts, actually?

    - by brainfrog
    Apple says about -detectConflictsForObject: If on the next invocation of save: object has been modified in its persistent store, the save fails. This allows optimistic locking for unchanged objects. Conflict detection is always performed on changed or deleted objects. So what does this mean? If I simply modify an managed object and then save the context, there is always a conflict detection happening? Does this conflict detection simply compare the timestamps of the "records" to see if the "new" data is actually "old"? Is that a conflict?

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  • Towards Ultra-Reusability for ADF - Adaptive Bindings

    - by Duncan Mills
    The task flow mechanism embodies one of the key value propositions of the ADF Framework, it's primary contribution being the componentization of your applications and implicitly the introduction of a re-use culture, particularly in large applications. However, what if we could do more? How could we make task flows even more re-usable than they are today? Well one great technique is to take advantage of a feature that is already present in the framework, a feature which I will call, for want of a better name, "adaptive bindings". What's an adaptive binding? well consider a simple use case.  I have several screens within my application which display tabular data which are all essentially identical, the only difference is that they happen to be based on different data collections (View Objects, Bean collections, whatever) , and have a different set of columns. Apart from that, however, they happen to be identical; same toolbar, same key functions and so on. So wouldn't it be nice if I could have a single parametrized task flow to represent that type of UI and reuse it? Hold on you say, great idea, however, to do that we'd run into problems. Each different collection that I want to display needs different entries in the pageDef file and: I want to continue to use the ADF Bindings mechanism rather than dropping back to passing the whole collection into the taskflow   If I do use bindings, there is no way I want to have to declare iterators and tree bindings for every possible collection that I might want the flow to handle  Ah, joy! I reply, no need to panic, you can just use adaptive bindings. Defining an Adaptive Binding  It's easiest to explain with a simple before and after use case.  Here's a basic pageDef definition for our familiar Departments table.  <executables> <iterator Binds="DepartmentsView1" DataControl="HRAppModuleDataControl" RangeSize="25"             id="DepartmentsView1Iterator"/> </executables> <bindings> <tree IterBinding="DepartmentsView1Iterator" id="DepartmentsView1">   <nodeDefinition DefName="oracle.demo.model.vo.DepartmentsView" Name="DepartmentsView10">     <AttrNames>       <Item Value="DepartmentId"/>         <Item Value="DepartmentName"/>         <Item Value="ManagerId"/>         <Item Value="LocationId"/>       </AttrNames>     </nodeDefinition> </tree> </bindings>  Here's the adaptive version: <executables> <iterator Binds="${pageFlowScope.voName}" DataControl="HRAppModuleDataControl" RangeSize="25"             id="TableSourceIterator"/> </executables> <bindings> <tree IterBinding="TableSourceIterator" id="GenericView"> <nodeDefinition Name="GenericViewNode"/> </tree> </bindings>  You'll notice three changes here.   Most importantly, you'll see that the hard-coded View Object name  that formally populated the iterator Binds attribute is gone and has been replaced by an expression (${pageFlowScope.voName}). This of course, is key, you can see that we can pass a parameter to the task flow, telling it exactly what VO to instantiate to populate this table! I've changed the IDs of the iterator and the tree binding, simply to reflect that they are now re-usable The tree binding itself has simplified and the node definition is now empty.  Now what this effectively means is that the #{node} map exposed through the tree binding will expose every attribute of the underlying iterator's collection - neat! (kudos to Eugene Fedorenko at this point who reminded me that this was even possible in his excellent "deep dive" session at OpenWorld  this year) Using the adaptive binding in the UI Now we have a parametrized  binding we have to make changes in the UI as well, first of all to reflect the new ID that we've assigned to the binding (of course) but also to change the column list from being a fixed known list to being a generic metadata driven set: <af:table value="#{bindings.GenericView.collectionModel}" rows="#{bindings.GenericView.rangeSize}"         fetchSize="#{bindings.GenericView.rangeSize}"           emptyText="#{bindings.GenericView.viewable ? 'No data to display.' : 'Access Denied.'}"           var="row" rowBandingInterval="0"           selectedRowKeys="#{bindings.GenericView.collectionModel.selectedRow}"           selectionListener="#{bindings.GenericView.collectionModel.makeCurrent}"           rowSelection="single" id="t1"> <af:forEach items="#{bindings.GenericView.attributeDefs}" var="def">   <af:column headerText="#{bindings.GenericView.labels[def.name]}" sortable="true"            sortProperty="#{def.name}" id="c1">     <af:outputText value="#{row[def.name]}" id="ot1"/>     </af:column>   </af:forEach> </af:table> Of course you are not constrained to a simple read only table here.  It's a normal tree binding and iterator that you are using behind the scenes so you can do all the usual things, but you can see the value of using ADFBC as the back end model as you have the rich pantheon of UI hints to use to derive things like labels (and validators and converters...)  One Final Twist  To finish on a high note I wanted to point out that you can take this even further and achieve the ultra-reusability I promised. Here's the new version of the pageDef iterator, see if you can notice the subtle change? <iterator Binds="{pageFlowScope.voName}"  DataControl="${pageFlowScope.dataControlName}" RangeSize="25"           id="TableSourceIterator"/>  Yes, as well as parametrizing the collection (VO) name, we can also parametrize the name of the data control. So your task flow can graduate from being re-usable within an application to being truly generic. So if you have some really common patterns within your app you can wrap them up and reuse then across multiple developments without having to dictate data control names, or connection names. This also demonstrates the importance of interacting with data only via the binding layer APIs. If you keep any code in the task flow generic in that way you can deal with data from multiple types of data controls, not just one flavour. Enjoy!

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  • How to preselect nodes using jsTree jQuery plug-in

    - by Ed Schembor
    I am using the jsTree jQuery plug-in with its "Checkbox" plug-in and using an async http request to lazy-load each level of the tree. All works great, except that I cannot get the tree to pre-select certain nodes after the first level. I am using the "selected" attribute to provide an array of ID's to preselect. ID's in the top level of the tree are correctly pre-selected. However, ID's in lower levels of the tree are not selected when the level loads. Am I missing something? Here is the constructor code: $(sDivID).tree( { data : { async : true, opts : {url : sURL} }, plugins:{ "checkbox" : {three_state : false} }, selected : myArrayOfIDs, ui:{ theme_name : "checkbox", dots : false, animation : 400 }, callback : { beforedata : function(NODE, TREE_OBJ) { return { id : $(NODE).attr("id") || 0, rand : Math.random().toString() } } } } )

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  • Are Multiple Iterators possible in php?

    - by artvolk
    Good day! I know that C# allows multiple iterators using yield, like described here: http://stackoverflow.com/questions/1754041/is-multiple-iterators-is-possible-in-c In PHP there is and Iterator interface. Is it possible to implement more than one iteration scenario for a class? More details (EDIT): For example I have class TreeNode implementing single tree node. The whole tree can be expressed using only one this class. I want to provide iterators for iterating all direct and indirect children of current node, for example using BreadthFirst or DepthFirst order. I can implement this Iterators as separate classes but doing so I need that tree node should expose it's children collection as public. C# pseudocode: public class TreeNode<T> { ... public IEnumerable<T> DepthFirstEnumerator { get { // Some tree traversal using 'yield return' } } public IEnumerable<T> BreadthFirstEnumerator { get { // Some tree traversal using 'yield return' } } }

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  • Thumbnails from HTML pages created and used automatically in web application

    - by Jesper Rønn-Jensen
    I am working on a Ruby on Rails app that visualizes product trees. The tree is built of nodes an everything is rendered in HTML/CSS3. Some of the products make several hundred SQL queries as the tree builds up (up to 800 queries on the biggest tree). I'd like to have small thumbnails of each tree to present it on an index page. So rendering each tree once again and modifying CSS to make a tiny representation is an option. But i think it's probably easier to generate thumbnails, crop, cache, and show these on the index page. Any ideas on how to do this? Any links/articles/blog posts that could help me?

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  • PyQt4: Why does Python crash on close when using QTreeWidgetItem?

    - by Rini
    I'm using Python 3.1.1 and PyQt4 (not sure how to get that version number?). Python is crashing whenever I exit my application. I've seen this before as a garbage collection issue, but this time I'm not sure how to correct the problem. This code crashes: import sys from PyQt4 import QtGui class MyWindow(QtGui.QMainWindow): def __init__(self, parent=None): QtGui.QMainWindow.__init__(self, parent) self.tree = QtGui.QTreeWidget(self) self.setCentralWidget(self.tree) QtGui.QTreeWidgetItem(self.tree) # This line is the problem self.show() app = QtGui.QApplication(sys.argv) mw = MyWindow() sys.exit(app.exec_()) If I remove the commented line, the code exits without a problem. If I remove the 'self.tree' parent from the initialization, the code exits without a problem. If I try to use self.tree.addTopLevelItem, the code crashes again. What could be the problem?

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  • yield – Just yet another sexy c# keyword?

    - by George Mamaladze
    yield (see NSDN c# reference) operator came I guess with .NET 2.0 and I my feeling is that it’s not as wide used as it could (or should) be.   I am not going to talk here about necessarity and advantages of using iterator pattern when accessing custom sequences (just google it).   Let’s look at it from the clean code point of view. Let's see if it really helps us to keep our code understandable, reusable and testable.   Let’s say we want to iterate a tree and do something with it’s nodes, for instance calculate a sum of their values. So the most elegant way would be to build a recursive method performing a classic depth traversal returning the sum.           private int CalculateTreeSum(Node top)         {             int sumOfChildNodes = 0;             foreach (Node childNode in top.ChildNodes)             {                 sumOfChildNodes += CalculateTreeSum(childNode);             }             return top.Value + sumOfChildNodes;         }     “Do One Thing” Nevertheless it violates one of the most important rules “Do One Thing”. Our  method CalculateTreeSum does two things at the same time. It travels inside the tree and performs some computation – in this case calculates sum. Doing two things in one method is definitely a bad thing because of several reasons: ·          Understandability: Readability / refactoring ·          Reuseability: when overriding - no chance to override computation without copying iteration code and vice versa. ·          Testability: you are not able to test computation without constructing the tree and you are not able to test correctness of tree iteration.   I want to spend some more words on this last issue. How do you test the method CalculateTreeSum when it contains two in one: computation & iteration? The only chance is to construct a test tree and assert the result of the method call, in our case the sum against our expectation. And if the test fails you do not know wether was the computation algorithm wrong or was that the iteration? At the end to top it all off I tell you: according to Murphy’s Law the iteration will have a bug as well as the calculation. Both bugs in a combination will cause the sum to be accidentally exactly the same you expect and the test will PASS. J   Ok let’s use yield! That’s why it is generally a very good idea not to mix but isolate “things”. Ok let’s use yield!           private int CalculateTreeSumClean(Node top)         {             IEnumerable<Node> treeNodes = GetTreeNodes(top);             return CalculateSum(treeNodes);         }             private int CalculateSum(IEnumerable<Node> nodes)         {             int sumOfNodes = 0;             foreach (Node node in nodes)             {                 sumOfNodes += node.Value;             }             return sumOfNodes;         }           private IEnumerable<Node> GetTreeNodes(Node top)         {             yield return top;             foreach (Node childNode in top.ChildNodes)             {                 foreach (Node currentNode in GetTreeNodes(childNode))                 {                     yield return currentNode;                 }             }         }   Two methods does not know anything about each other. One contains calculation logic another jut the iteration logic. You can relpace the tree iteration algorithm from depth traversal to breath trevaersal or use stack or visitor pattern instead of recursion. This will not influence your calculation logic. And vice versa you can relace the sum with product or do whatever you want with node values, the calculateion algorithm is not aware of beeng working on some tree or graph.  How about not using yield? Now let’s ask the question – what if we do not have yield operator? The brief look at the generated code gives us an answer. The compiler generates a 150 lines long class to implement the iteration logic.       [CompilerGenerated]     private sealed class <GetTreeNodes>d__0 : IEnumerable<Node>, IEnumerable, IEnumerator<Node>, IEnumerator, IDisposable     {         ...        150 Lines of generated code        ...     }   Often we compromise code readability, cleanness, testability, etc. – to reduce number of classes, code lines, keystrokes and mouse clicks. This is the human nature - we are lazy. Knowing and using such a sexy construct like yield, allows us to be lazy, write very few lines of code and at the same time stay clean and do one thing in a method. That's why I generally welcome using staff like that.   Note: The above used recursive depth traversal algorithm is possibly the compact one but not the best one from the performance and memory utilization point of view. It was taken to emphasize on other primary aspects of this post.

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  • Multiple Context menus in PyQt based on mouse location

    - by Nader
    I have a window with multiple tables using QTableWidget (PyQt). I created a popup menu using the right click mouse and it works fine. However, I need to create different popup menu based on which table the mouse is hovering over at the time the right mouse is clicked. How can I get the mouse to tell me which table it is hovering over? or, put in another way, how to implement a method so as to have a specific context menu based on mouse location? I am using Python and PyQt. My popup menu is developed similar to this code (PedroMorgan answer from Qt and context menu): class Foo( QtGui.QWidget ): def __init__(self): QtGui.QWidget.__init__(self, None) # Toolbar toolbar = QtGui.QToolBar() # Actions self.actionAdd = toolbar.addAction("New", self.on_action_add) self.actionEdit = toolbar.addAction("Edit", self.on_action_edit) self.actionDelete = toolbar.addAction("Delete", self.on_action_delete) # Tree self.tree = QtGui.QTreeView() self.tree.setContextMenuPolicy( Qt.CustomContextMenu ) self.connect(self.tree, QtCore.SIGNAL('customContextMenuRequested(const QPoint&)'), self.on_context_menu) # Popup Menu self.popMenu = QtGui.QMenu( self ) self.popMenu.addAction( self.actionEdit ) self.popMenu.addAction( self.actionDelete ) self.popMenu.addSeparator() self.popMenu.addAction( self.actionAdd ) def on_context_menu(self, point): self.popMenu.exec_( self.tree.mapToGlobal(point) )

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  • How to set initial size of a TreeViewer?

    - by Jeff
    Hello, I'm using a TreeViewer within a jface WizardPage and the initial input into the tree causes the WizardPage to grow vertically so that it can show all of the tree's values. When expanding one of the tree's values, then the vertical scrollbar works as expected. I'd like to be able to set the tree's size initially so that it is fixed and the scrollbar is already shown when the WizardPage is first drawn, but doing this isn't particularly obvious to me - the setSize method on the TreeViewer's Tree doesn't seem to do anything. Any help would be appreciated!

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  • Does JSLint parse DOM functions?

    - by Paul
    I tried to use the parse() function of JSLint to parse three pieces of JavaScript code: function(b, c){var a = b + c; return a; } window.addEventListener('click', click_hanlder, true); document.documentElement.innerHTML; Here's the code, which is copied and pasted from the JSLint self-parse example: ` try { parse = make_parse(); var source = "something to parse";//replaced by the code above tree = parse(source); if (tree) { document.write(JSON.stringify(tree, ['key', 'name', 'message', 'value', 'arity', 'first', 'second', 'third', 'fourth'], 4)); } } catch (e) { document.write(JSON.stringify(e, ['name', 'message', 'from', 'to', 'key', 'value', 'arity', 'first', 'second', 'third', 'fourth'], 4)); } ` The output: returns a correct tree. returns a tree with only one node of "window". crashes the browser. I'm wondering whether JSLint doesn't support DOM function.

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