I have a component which consists of two children component A and B. However, the visibility of showing either A or B can only be determined after the page rendering started. I tried to do this but got back the following error:
Cannot modify component hierarchy after render phase has started
So, is there any way to change the visibility of the children components in my case?
I'm not exactly sure if I understand your problem.
I assume that you have 2 containers and want to display only one of them. If that is the case you can simply extend the onConfigure() method and change the visibility the way you want it to. This method will be called once during each rendering and is therefore preferred over extending the isVisible() method (which is called multiple times during each request).
private IModel<Boolean> switchModel = Model.of(Boolean.FALSE);
#Override
protected void onInitialize() {
super.onInitialize();
WebMarkupContainer container1 = new WebMarkupContainer("container1") {
#Override
protected void onConfigure() {
super.onConfigure();
setVisible(Boolean.TRUE.equals(switchModel.getModelObject()));
}
};
add(container1);
WebMarkupContainer container2 = new WebMarkupContainer("container2") {
#Override
protected void onConfigure() {
super.onConfigure();
setVisible(Boolean.FALSE.equals(switchModel.getModelObject()));
}
};
add(container2);
}
Related
I am making a program using the amazing libGDX+scene2d API and I structured it as follows:
I have a single MyGame instance, holding a single PolygonSpriteBatch instance.
There is an abstract MyScreen class, holding a MyStage class (see below)
Then there are lots of different screen classes that inherit from MyScreen, and instantiate each other at will.
(in all cases, removing the "My" gives you the name of the respective library class that it extends)
This model worked fine, until I encountered some problems to perform actions between screens using the Action system. I decided then that it would be a good idea to have a single OmnipresentActor belonging to MyGame that, as the name says, is present in every scene. So I modified MyStage to look more or less like this:
public class MyStage extends Stage {
public MyStage(MyGame g) {
super(new FitViewport(MyGame.WIDTH, MyGame.HEIGHT), g.batch);
addActor(game.omnipresentInvisibleActor);
}
#Override
public void clear() {
unfocusAll();
getRoot().clearActions();
getRoot().clearListeners();
removeActorsButNotListenersNorActions();
}
public void removeActorsButNotListenersNorActions() {
for (Actor a : getActors()) if (a.getClass()!= OmnipresentInvisibleActor.class) a.remove();
}
It followed a painful debugging phase, until I found out the following:
public PresentationScreen(MyGame g) {
// super() call and other irrelevant/already debugged code
System.out.println("PRINT_BEFORE: "+ stage.getActors().toString()); // OmnipresentActor is there
mainMenuScreen = new MainMenuScreen(game);
System.out.println("PRINT_AFTER: "+ stage.getActors().toString()); // OmnipresentActor is not there anymore, but was added to the mainMenuScreen
the "PRINT_BEFORE" statement shows that the stage holds the omnipresentActor. In "PRINT_AFTER" it isn't there anymore, whereas mainMenuScreen is indeed holding it. So my question, now more precise:
does scene2d prevent this to happen, or am I doing something wrong here?
Answers much appreciated! Cheers
An actor can only be a member of one stage: Thanks to #Tenfour04 for confirming that. The explanation is quite clear after doing a little research:
Stage.addActor() looks like this:
(here the github code of Stage.java)
/** Adds an actor to the root of the stage.
* #see Group#addActor(Actor) */
public void addActor (Actor actor) {
root.addActor(actor);
}
whereas root is simply initialized as a group in the Stage constructor: root = new Group();.
And Group.addActor() looks like this:
(here the github code of Group.java)
/** Adds an actor as a child of this group. The actor is first removed from its parent group, if any. */
public void addActor (Actor actor) {
if (actor.parent != null) actor.parent.removeActor(actor, false);
children.add(actor);
actor.setParent(this);
actor.setStage(getStage());
childrenChanged();
}
So in the tree first lines is the answer: when creating the new stage, if the actor to add already has a parent, it is removed from its current parent. So, There are two possible solutions to the problem I enounced:
SOLUTION 1: Override addActor removing the if statement, or any other alteration of the library, which I'm not sure if it would work. I rather think this could be very problematic, for instance it could prevent the stages from disposing correctly
SOLUTION 2: Change the design so you don't need an omnipresent actor, nor changing/reimplementing the libraries. For the moment this is what I've done based on this answer, it isn't very clean but it works so far:
1) In the MyScreen class added the following fields:
private boolean watchingTemp;
private Actor watchActorTemp;
private Action actionTemp;
2) Then added this method:
public void addActionOnStageAfterActorEndsHisActions(Actor actor, Action action) {
watchActorTemp = actor;
actionTemp = action;
watchingTemp = true;
}
3) then in the render method, I added the following:
if (watchingTemp && !watchActorTemp.hasActions()) {
watchingTemp = false;
stage.addAction(actionTemp);
}
4) finally, when wishing to perform an action at a screen transition (and eventually disposing the first one), you can do something like this: I use something similar when clicking on a door between screens
public void movePlayerTHENgotoNewScreen(float xPos, float yPos, whatever else...) {
game.player.walkToAnyPoint(xPos, yPos);
yourFavoriteScreen.addActionOnStageAfterActorEndsHisActions(game.player, gotoNewScreen(wathever else...));
}
Hope it helps!
In a MvvmCross app, I have a page with the classic chat behavior (WhatsApp like): this page shows the history of messages exchanged between two users with the last message at the bottom of the list.
I've successfully implemented the view in Windows Phone 8.1, but I'm struggling with a problem in Android.
I'll give you a short introduction and description of my problem and next I'll go through technical details.
INTRODUCTION
Actually, my need is to apply different style to messages sent by different users: tipically align left messages sent from other user and align right messages sent by me (I do this through the weight property); I need to apply a different drawable background and set different gravity property also.
I use custom binding because, AFAIK, those properties cannot be binded with classic binding: local:MvxBind="Gravity MyPropery" doesn't work because there is no Gravity property.
So, I have of course two axml files:
the first one contains the Mvx.MvxListView
the second one contains the item template for MvxListView
And I've created three different custombinding (for Background, Gravity and Weight) following these guides:
http://slodge.blogspot.it/2013/06/n28-custom-bindings-n1-days-of-mvvmcross.html
In MvvmCross how do I do custom bind properties
THE PROBLEM
I want that, when a user opens the chat View, the list widget shows automatically the last message. To accomplish this, I scroll programmatically the list to the last message and this seems to be the problem.
If I don't scroll programmatically, when I open the page and scroll manually to the end of the page, all custom bindings are applied successfully: I can see messages aligned right and left, with correct background and weight applied.
If I force the scroll programmatically, when I open the page I see a strange behavior: all the messages are present (classic binding, such as Text property, have been successfully applied), but custom bindings are missing. All the messages have the same background and are all left aligned.
BUT, if I scroll manually up and down, the custom binding are processed and the messages are displayed with right style.
DEBUG ANALYSIS
To debug the behaviour I've put a simple static counter in a custom binding procedure to track every time the function is processed.
public class LinearLayoutWeightTargetBinding : MvxAndroidTargetBinding
{
public static int debugCounter = 0;
public LinearLayoutWeightTargetBinding(object target) : base(target)
{
}
protected LinearLayout MyTarget
{
get { return (LinearLayout)Target; }
}
public override Type TargetType { get { return typeof(bool); } }
protected override void SetValueImpl(object target, object value)
{
var ll = (LinearLayout)target;
var itsMe = (bool)value;
var weight = itsMe ? (float)20.0 : (float)5.0;
var layoutParams = new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WrapContent, weight);
ll.LayoutParameters = layoutParams;
Log.Debug("MeeCHAT", string.Format("LinearLayoutWeightTargetBinding::SetValueImpl::ItsMe:{0} - counter:{1}", itsMe, ++debugCounter));
}
public override MvxBindingMode DefaultMode { get {return MvxBindingMode.TwoWay;} }
}
By this way I saw that actually by scrolling up and down the custom bindings are applied (debugCounter increases correctly).
BUT when I apply the programmatically scroll, only the first 10 items are processed by the custom bindings and this seems the reason why I see the messages without the right style. Because I have a long list, only the first 10 items are processed but they are not visible (they are out of the visible area) and the visibile items have not been processed.
TECHNICAL DETAILS
Here are some details related to technical aspects of my app. I try to give you all important aspects.
ORGANIZATION OF THE VIEWS
By following the approach described by Greg Shackles in this article http://gregshackles.com/presenters-in-mvvmcross-navigating-android-with-fragments/ I have just one general Activity for the app and one Fragment for each View; then through a Presenter is possible to activate the right ViewModel and manage the stack of the navigation.
The Fragment for the View where I have the Mvx.MvxListView widget is
public class MyMatchersChatView : MvxFragment
{
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
var ignore = base.OnCreateView(inflater, container, savedInstanceState);
var result = this.BindingInflate(Resource.Layout.MyMatchersChatView, null);
var headerFrame = result.FindViewById<FrameLayout>(Resource.Id.headerFrameMyMatchersChatView);
var headerWidget = new HeaderWidget() { ViewModel = this.ViewModel };
var tran = ChildFragmentManager.BeginTransaction();
tran.Add(headerFrame.Id, headerWidget, "headerMyMatchersChat");
tran.Commit();
var listView = result.FindViewById<MvxListView>(Resource.Id.messagesList);
listView.SetSelection(listView.Adapter.Count - 1); // Scroll to the end of the list
return result;
}
}
The statement listView.SetSelection(listView.Adapter.Count - 1); force the list to scroll to the end.
Last two things: how the custom bindings are registered and how are applied in axml file.
REGISTRATION OF CUSTOM BINDING
In Setup.cs I have:
protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry)
{
base.FillTargetFactories(registry);
registry.RegisterFactory(new MvxCustomBindingFactory<LinearLayout>("CustomWeight",
(b) => new LinearLayoutWeightTargetBinding(b)));
}
APPLYING OF CUSTOM BINDING
In my axml I have:
<LinearLayout
android:orientation="horizontal"
android:layout_width="0dp"
android:layout_height="wrap_content"
local:MvxBind="CustomWeight IsCurrentUser">
LISTVIEW AND VIEWMODEL
Here is the code of ListView
<Mvx.MvxListView
android:id="#+id/messagesList"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
local:MvxBind="ItemsSource MyMessages"
local:MvxItemTemplate="#layout/mymatcherschatview_itemtemplate" />
and the property in ViewModel
private IEnumerable<MyMatchMessageModel> _myMessages;
public IEnumerable<MyMatchMessageModel> MyMessages
{
get { return _myMessages; }
set
{
_myMessages = value;
RaisePropertyChanged(() => MyMessages);
}
}
ENVIRONMENT
Finally, here is my environment:
Visual Studio 2015
MvvmCross 3.5.1
Core targets: .NET Framework 4.5, Windows 8, ASP.NET Core 5.0, Windows Phone 8.1, Xamarin.Android, Xamarin.iOS, Xamarin.iOS (Classic)
The Android app target is API Level 19 (Xamarin.Android v4.4 Support)
Xamarin 3.11.1450.0
Xamarin.Android 5.1.6.7
Someone can help me to understand if I'm doing something wrong?
Thanks for reading and for any help!
>>EDIT 1<<
I've changed my layout by adding stackFromBottom and transcriptMode properties and by removing the scrolling to below programmatically in Fragment obtaining an auto-scroll behavior, but the problem still remains: to see messages with correct style I have to manually scroll up and down (to activate the custom bindings)
Here is the new axml...
<Mvx.MvxListView
android:id="#+id/messagesList"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:stackFromBottom="true"
android:transcriptMode="alwaysScroll"
local:MvxBind="ItemsSource MyMessages"
local:MvxItemTemplate="#layout/mymatcherschatview_itemtemplate" />
...and the new code in Fragment
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
var ignore = base.OnCreateView(inflater, container, savedInstanceState);
var result = this.BindingInflate(Resource.Layout.MyMatchersChatView, null);
var headerFrame = result.FindViewById<FrameLayout>(Resource.Id.headerFrameMyMatchersChatView);
var headerWidget = new HeaderWidget() { ViewModel = this.ViewModel };
var tran = ChildFragmentManager.BeginTransaction();
tran.Add(headerFrame.Id, headerWidget, "headerMyMatchersChat");
tran.Commit();
return result;
}
First thing I would do is to make sure that your custom binding is always getting called.
Set a breakpoint on the SetValueImpl() method and check it´s getting called on those problematic items. If that happens, then the issue relies on the view no getting updated for any reason and you should work on that. If it doesn´t break, you will know for sure it´s a custom binding problem (possibly a bug) in MvxAdapter.
If you find out it´s the second one. I would suggest getting rid of your custom binding and creating your own ChatListAdapter : MvxAdapter as follows:
public class CoolChatListAdapter : MvxAdapter
{
public CoolChatListAdapter(Context context, IMvxAndroidBindingContext bindingContext) : base(context, bindingContext)
{
}
protected override View GetBindableView(View convertView, object source, int templateId)
{
var item = source as MyMatchMessageModel;
var weight = item.IsCurrentUser ? (float) 20.0 : (float) 5.0;
var ll = (LinearLayout) convertView;
var layoutParams = new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WrapContent, weight);
ll.LayoutParameters = layoutParams;
return base.GetBindableView(convertView, source, templateId);
}
}
Then, in your android view:
var adapter = new ChatListAdapter(this, (IMvxAndroidBindingContext)BindingContext);
_chatList = FindViewById<MvxListView>(Resource.Id.chat_list_view);
_chatList.Adapter = adapter;
I am new to automation and want to create an automation test which can do following:
Open one tab --- click and get some info from that tab
Switch to another tab --- click and get some info from this tab now.
Compare the infos.
We use Page Object Model to get info from one page. However the moment, I switch to another tab -- it switches the tab successfully but does not locate any element on it.
Any idea ?
Questions I would ask is,
Is the element locator correct?
Is this a unique element locator?
Is this a synchronization issue? Are you waiting enough for the page to load before finding the element?
Is this problem particular to a browser? Is it consistent across?
Also make sure you pass on the driver object from one page object to the other. Like,
public class PageOne {
public PageOne(WebDriver driver) {
//do something in constructor
}
public void someMethodInPage1() {
driver.findElement(By.id("button1")).click();
PageTwo pageTwo = new PageTwo(driver);
pageTwo.someMethodInPage2();
}
}
public class PageTwo {
private WebDriver driver;
public PageTwo(WebDriver driver) {
//do something in constructor
this.driver = driver;
}
public void someMethodInPage2() {
driver.findElement(By.id("button2")).click();
}
}
I want to use JCheckBoxMenuItems in a JPopupMenu. It works, but the problem is that the popup menu disappears when a checkbox item has been checked or unchecked. So if one wants to check/uncheck several items, the popup needs to be launched repeatedly, which is irritating.
Curiously, if I use just plain JCheckBox items in the menu (instead of JCheckBoxMenuItems), the behavior is just as it should be: the popup stays there and the checkboxes can be checked/unchecked. Once done, the popup can be closed just by clicking outside it.
How do I make the popup to behave like that when the items there are JCheckBoxMenuItems? I would prefer using JCheckBoxMenuItems because of their looks.
Well, found working answer from http://forums.sun.com/thread.jspa?threadID=5432911. Basically, create a custom UI:
public class StayOpenCheckBoxMenuItemUI extends BasicCheckBoxMenuItemUI {
#Override
protected void doClick(MenuSelectionManager msm) {
menuItem.doClick(0);
}
public static ComponentUI createUI(JComponent c) {
return new StayOpenCheckBoxMenuItemUI();
}
}
And set it in the JCheckBoxMenuItem:
myJCheckBoxMenuItem.setUI(new StayOpenCheckBoxMenuItemUI());
Don't know if this is the most elegant possible solution, but works perfectly.
I ran into an issue with the nice Joonas Pulakka's answer because the "UIManager lookandFeel" was ignored.
I found the nice trick below on http://tips4java.wordpress.com/2010/09/12/keeping-menus-open/
The point is to reopen immediatly the menu after it has been closed, it's invisible and keep the application look and feel and behavior.
public class StayOpenCBItem extends JCheckBoxMenuItem {
private static MenuElement[] path;
{
getModel().addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
if (getModel().isArmed() && isShowing()) {
path = MenuSelectionManager.defaultManager().getSelectedPath();
}
}
});
}
public StayOpenCBItem(String text) {
super(text);
}
#Override
public void doClick(int pressTime) {
super.doClick(pressTime);
MenuSelectionManager.defaultManager().setSelectedPath(path);
}
}
I found a much easier solution for this problem
JCheckBoxMenuItem menuItem = new JCheckBoxMenuItem("sample");
menuItem.putClientProperty("CheckBoxMenuItem.doNotCloseOnMouseClick", Boolean.TRUE);
I found this solution while reading the code from
BasicMenuItemUI.doNotCloseOnMouseClick()
I'm trying to create a titled border frame in GWT, which results in this:
This can be done using HTML fieldset and legend tags, such as
<fieldset>
<legend>Connection parameters</legend>
... the rest ...
</fieldset>
I want to create a custom widget in GWT that implements that. I managed to do that, but the problem is that events that happen inside the widget (button click etc) does not get fired although I have added the handler.
My implementation of the widget is as follows:
public class TitledPanel extends Widget {
private Element legend;
private Widget content = null;
public TitledPanel() {
Element fieldset = DOM.createFieldSet();
legend = DOM.createLegend();
DOM.appendChild(fieldset, legend);
setElement(fieldset);
}
public TitledPanel(String title) {
this();
setTitle(title);
}
#Override
public String getTitle() {
return DOM.getInnerHTML(legend);
}
#Override
public void setTitle(String html) {
DOM.setInnerHTML(legend, html);
}
public Widget getContent() {
return content;
}
public void setContent(Widget content) {
if (this.content != null) {
DOM.removeChild(getElement(), this.content.getElement());
}
this.content = content;
DOM.appendChild(getElement(), content.getElement());
}
}
Do I need to extend Composite, or need to manually reroute the events, or is there other ways?
I think you're looking for CaptionPanel:
A panel that wraps its contents in a border with a caption that appears in the upper left corner of the border. This is an implementation of the fieldset HTML element.
I think the problem here is that you just call DOM.appendChild - this doesn't cause the TitledPanel to adopt the Widget. The normal course of action is that you extend Composite and then call initWidget(Widget widget) - inside the hood it calls widget.setParent(this);, which in turn makes the parent adopt this widget and attach it to the browser's document. However com.google.gwt.user.client.ui.Widget.setParent(Widget) is only package-visible so you can't call it from your code (after, for example, DOM.appendChild).
I'd recommend reading Widget Best Practices / Widget Building, especially the Clean up after yourself and/or look at the source code for some GWT Widgets, to get the idea how the GWT sees custom widget creation.
And, as Robert suggested, CaptionPanel is the safer route :)