If I scroll on my table to the right it will automatically scroll back to the left. I have no own implementation for scrolling, all is done by the TableView. Has anyone seen this before? If I test it on windows I have no issue.
compile "org.javafxports:jfxdvk:8.60.13"
javafxportsVersion = '8.60.13'
This issue is more related to javafx. If the "IS_TOUCH_SUPPORTED" flag is set the scroll bar is set to visible false after use (VirtualFlow). A change listener onVisible does then a updateHbar(). And because of hbar.isVisible() the scroll var value is set to 0.
I did not want to change "IS_TOUCH_SUPPORTED". That's why I create a own skin which only creates a custom virtual flow. The custom virtual flow is also very simple I only set the tempVisibility to true via reflection. And I also overwrite the startSBReleasedAnimation() method and do nothing inside.
public class CustomVirtualFlow<T extends IndexedCell<?>> extends VirtualFlow<T> {
public CustomVirtualFlow() {
super();
try {
final Field field = VirtualFlow.class.getDeclaredField("tempVisibility");
field.setAccessible(true);
field.setBoolean(this, true);
} catch (final Exception e) {
}
}
/*
* (non-Javadoc)
*
* #see com.sun.javafx.scene.control.skin.VirtualFlow#startSBReleasedAnimation()
*/
#Override
protected void startSBReleasedAnimation() {
// do not call the super.startSBReleasedAnimation()
}
Related
I have found that on iOS, OnAppearing is called when the page literally appears on the screen, whereas on Android, it's called when it's created.
I'm using this event to lazily construct an expensive to construct view but obviously the Android behaviour defeats this.
Is there some way of knowing on Android when a screen literally appears on the screen?
You can use the event:
this.Appearing += YourPageAppearing;
Otherwise, you should use the methods of the Application class that contains the lifecycle methods:
protected override void OnStart()
{
Debug.WriteLine ("OnStart");
}
protected override void OnSleep()
{
Debug.WriteLine ("OnSleep");
}
protected override void OnResume()
{
Debug.WriteLine ("OnResume");
}
On Android, Xamarin.Forms.Page.OnAppearing is called immediately before the page's view is shown to user (not when the page is "created" (constructed)).
If you want an initial view to appear quickly, by omitting an expensive sub-view, use a binding to make that view's IsVisible initially be "false". This will keep it out of the visual tree, avoiding most of the cost of building it. Place the (invisible) view in a grid cell, whose dimensions are constant (either in DPs or "*" - anything other than "Auto".) So that layout will be "ready" for that view, when you make it visible.
APPROACH 1:
Now you just need a binding in view model that will change IsVisible to "true".
The simplest hack is to, in OnAppearing, fire an action that will change that variable after 250 ms.
APPROACH 2:
The clean alternative is to create a custom page renderer, and override "draw".
Have draw, after calling base.draw, check an action property on your page.
If not null, invoke that action, then clear it (so only happens once).
I do this by inheriting from a custom page base class:
XAML for each of my pages (change "ContentPage" to "exodus:ExBasePage"):
<exodus:ExBasePage
xmlns:exodus="clr-namespace:Exodus;assembly=Exodus"
x:Class="YourNamespace.YourPage">
...
</exodus:ExBasePage>
xaml.cs:
using Exodus;
// After creating page, change "ContentPage" to "ExBasePage".
public partial class YourPage : ExBasePage
{
...
my custom ContentPage. NOTE: Includes code not needed for this, related to iOS Safe Area and Android hardward back button:
using Xamarin.Forms;
using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
namespace Exodus
{
public abstract partial class ExBasePage : ContentPage
{
public ExBasePage()
{
// Each sub-class calls InitializeComponent(); not needed here.
ExBasePage.SetupForLightStatusBar( this );
}
// Avoids overlapping iOS status bar at top, and sets a dark background color.
public static void SetupForLightStatusBar( ContentPage page )
{
page.On<Xamarin.Forms.PlatformConfiguration.iOS>().SetUseSafeArea( true );
// iOS NOTE: Each ContentPage must set its BackgroundColor to black or other dark color (when using LightContent for status bar).
//page.BackgroundColor = Color.Black;
page.BackgroundColor = Color.FromRgb( 0.3, 0.3, 0.3 );
}
// Per-platform ExBasePageRenderer uses these.
public System.Action NextDrawAction;
/// <summary>
/// Override to do something else (or to do nothing, i.e. suppress back button).
/// </summary>
public virtual void OnHardwareBackButton()
{
// Normal content page; do normal back button behavior.
global::Exodus.Services.NavigatePopAsync();
}
}
}
renderer in Android project:
using System;
using Android.Content;
using Android.Views;
using Android.Graphics;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
using Exodus;
using Exodus.Android;
[assembly: ExportRenderer( typeof( ExBasePage ), typeof( ExBasePageRenderer ) )]
namespace Exodus.Android
{
public class ExBasePageRenderer : PageRenderer
{
public ExBasePageRenderer( Context context ) : base( context )
{
}
protected override void OnElementChanged( ElementChangedEventArgs<Page> e )
{
base.OnElementChanged( e );
var page = Element as ExBasePage;
if (page != null)
page.firstDraw = true;
}
public override void Draw( Canvas canvas )
{
try
{
base.Draw( canvas );
var page = Element as ExBasePage;
if (page?.NextDrawAction != null)
{
page.NextDrawAction();
page.NextDrawAction = null;
}
}
catch (Exception ex)
{
// TBD: Got Disposed exception on Android Bitmap, after rotating phone (in simulator).
// TODO: Log exception.
Console.WriteLine( "ExBasePageRenderer.Draw exception: " + ex.ToString() );
}
}
}
}
To do some action after the first time the page is drawn:
public partial class YourPage : ExBasePage
{
protected override void OnAppearing()
{
// TODO: OnPlatform code - I don't have it handy.
// On iOS, we call immediately "DeferredOnAppearing();"
// On Android, we set this field, and it is done in custom renderer.
NextDrawAction = DeferredOnAppearing;
}
void DeferredOnAppearing()
{
// Whatever you want to happen after page is drawn first time:
// ((MyViewModel)BindingContext).ExpensiveViewVisible = true;
// Where MyViewModel contains:
// public bool ExpensiveViewVisible { get; set; }
// And your XAML contains:
// <ExpensiveView IsVisible={Binding ExpensiveViewVisible}" ... />
}
}
NOTE: I do this differently on iOS, because Xamarin Forms on iOS (incorrectly - not to spec) calls OnAppearing AFTER the page is drawn.
So I have OnPlatform logic. On iOS, OnAppearing immediately calls DeferredOnAppearing. On Android, the line shown is done.
Hopefully iOS will eventually be fixed to call OnAppearing BEFORE,
for consistency between the two platforms.
If so, I would then add a similar renderer for iOS.
(The current iOS implementation means there is no way to update a view before it appears a SECOND time, due to popping the nav stack.
instead, it appears with outdated content, THEN you get a chance
to correct it. This is not good.)
I am Trying to add a dropListener so I can Drop and text into a draw2d Label ,in GEf Editor , Can anyone help how Can I do that. An example will be great.
To respond to drop events on a GEF edit part viewer you have to install on the viewer itself an implementation of org.eclipse.jface.util.TransferDropTargetListener that understands transfers of type org.eclipse.swt.dnd.TextTransfer and that creates some kind of org.eclipse.gef.Request that can be handled by an org.eclipse.gef.EditPolicy installed on the target org.eclipse.gef.EditPart.
You have to understand that both the Request and the EditPolicy allow you to customize the drop behavior on a EditPart basis. As a consequence, I can show you an example that is actually fully functional, but feel free to customize it to your real needs.
First create the TransferDropTargetListener:
public class TextTransferDropTargetListener extends AbstractTransferDropTargetListener {
public TextTransferDropTargetListener(EditPartViewer viewer) {
super(viewer, TextTransfer.getInstance());
}
#Override
protected void handleDragOver() {
getCurrentEvent().feedback = DND.FEEDBACK_SCROLL | DND.FEEDBACK_EXPAND;
super.handleDragOver();
}
#Override
protected Request createTargetRequest() {
return new ChangeBoundsRequest(REQ_ADD);
}
#Override
protected void updateTargetRequest() {
ChangeBoundsRequest request = (ChangeBoundsRequest) getTargetRequest();
request.setEditParts(Collections.EMPTY_LIST);
request.setLocation(getDropLocation());
}
#Override
protected void handleDrop() {
super.handleDrop();
if (getCurrentEvent().detail != DND.DROP_NONE) {
getViewer().setSelection(StructuredSelection.EMPTY);
getViewer().getControl().setFocus();
}
}
#Override
protected Command getCommand() {
String text = (String) getCurrentEvent().data;
List<IEntityPart> editParts = new ArrayList<IEntityPart>();
//
// using the 'text' variable you have to create
// a new EditPart that would eventually replace the old one.
//
editParts.add(createNewLabelPart());
ChangeBoundsRequest request = (ChangeBoundsRequest) getTargetRequest();
request.setEditParts(editParts);
return super.getCommand();
}
}
then install the listener in the graphical viewer constructor using the following statement:
addDropTargetListener(new TextTransferDropTargetListener(this));
finally ensure that an EditPolicy that understands requests of type REQ_ADD (maybe you already added one that extends LayoutEditPolicy or ContainerEditPolicy) is installed on the target EditPart, which is usually done in the AbstractEditPart.createEditPolicies().
To better understand the chain of responsibilities, I suggest you to have a look at the super implementation of the TransferDropTargetListener.getCommand() method.
In my application i have a Custom AlertView, which works quite good so far. I can open it the first time, do, what i want to do, and then close it. If i want to open it again, i'll get
java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first
so, here some code:
public Class ReadingTab
{
...
private AlertDialog AD;
...
protected override void OnCreate(Bundle bundle)
{
btnAdd.Click += delegate
{
if (IsNewTask)
{
...
AlertDialog.Builer adb = new AlertDialog.Builer(this);
...
View view = LayoutInflater.Inflate(Resource.Layout.AlertDView15ET15TVvert, null);
adb.setView(view)
}
AD = adb.show();
}
}
}
that would be the rough look of my code.
Inside of btnAdd are two more buttons, and within one of them (btnSafe) i do AD.Dismiss() to close the Alert dialoge, adb.dispose() hasn't done anything.
the first time works fine, but when i call it the secon time, the debugger holds at AD = adb.show(); with the Exception mentioned above.
So what do i have to do, to remove the Dialoge from the parent? i can't find removeView() anywhere.
If you are setting up an AlertView once and then using it in multiple places (especially if you are using the same AlertView across different Activities) then you should consider creating a static AlertDialog class that you can then call from all over the place, passing in the current context as a parameter each time you want to show it. Then when a button is clicked you can simply dismiss the dialog and set the instance to null. Here is a basic example:
internal static class CustomAlertDialog
{
private static AlertDialog _instance;
private const string CANCEL = #"Cancel";
private const string OK = #"OK";
private static EventHandler _handler;
// Static method that creates your dialog instance with the given title, message, and context
public static void Show(string title,
string message,
Context context)
{
if (_instance != null)
{
throw new Exception(#"Cannot have more than one confirmation dialog at once.");
}
var builder = new AlertDialog.Builder(context);
builder.SetTitle(title);
builder.SetMessage(message);
// Set buttons and handle clicks
builder.SetPositiveButton(OK, delegate { /* some action here */ });
builder.SetNegativeButton(CANCEL, delegate { /* some action here */});
// Create a dialog from the builder and show it
_instance = builder.Create();
_instance.SetCancelable(false);
_instance.Show();
}
}
And from your Activity you would call your CustomAlertDialog like this:
CustomAlertDialog.Show(#"This is my title", #"This is my message", this);
I am doing a project in Vaadin 7. In that I need to change the theme of a page.
In Vaadin 6, there is a function called 'setTheme()'. so that I can change the theme using that function wherever I want in my code.
But, In Vaadin 7, I couldn't find any like that.
I know there will be a way to do it.
And also how to apply changes on the UI when I change a theme?
Will it be changed automatically? (or)
ICEPush gonna help me?
In Vaadin 7 the method 'setTheme()' has been replaced with the new Annotation #Theme. The "on the fly theme change" is not possible in Vaadin 7.
There is a disucssion in this Vaadin Forum Thread about the on fly theme change in Vaadin 7. You should have a look on it.
setTheme functionality has been introduced in Vaadin 7.3.0: https://vaadin.com/wiki/-/wiki/Main/Changing+theme+on+the+fly
you can try this for Vaadin 7:
Create your own UIProvider
Register your UIProvider in root UI
Switch theme in UIProvider and trigger page reload
DynamicThemeUIProvider.java
public class DynamicThemeUIProvider extends UIProvider {
private String currentTheme = "reindeer";
#Override
public Class<? extends UI> getUIClass(UIClassSelectionEvent event) {
return DemoUI.class;
}
public void setTheme(String theme) {
currentTheme = theme;
}
public String getTheme(UICreateEvent event) {
return currentTheme;
}
}
DemoUI.java
public class DemoUI extends UI {
private DynamicThemeUIProvider provider;
#Override
protected void init(VaadinRequest request) {
provider = new DynamicThemeUIProvider();
getSession().addUIProvider(provider);
}
public DynamicThemeUIProvider getDynamicThemeUIProvider() {
return provider;
}
}
Then on a component which switches the theme:
#Override
public void valueChange(ValueChangeEvent event) {
DemoUI ui = (DemoUI) getUI();
DynamicThemeUIProvider uiProvider = ui.getDynamicThemeUIProvider();
if (uiProvider == null) {
return;
}
uiProvider.setTheme("reindeer");
try {
String value = (String) event.getProperty().getValue();
uiProvider.setTheme(value.toLowerCase());
} catch (Exception e) {
e.printStackTrace();
}
ui.getPage().getJavaScript().execute("document.location.reload(true)"); // page refresh
}
Since I used custom themes, I have made it pretty simple. I used a toggle button and executed the required piece of code every time.
JavaScript.getCurrent().execute("document.body.className = document.body.className.replace(\"theme1\",\"theme2\"); ");
JavaScript.getCurrent().execute("document.body.className = document.body.className.replace(\"theme2\",\"theme1\"); ");
My css file will be like this.
.theme1 .v-button {
/* some css attribute */
}
.theme2 .v-button {
/* some css attribute */
}
Believe me; the theme switch is very very fast since the browser itself do the trick to switch the theme rather than asking the Vaadin server to do the switch.
Regarding themes for charts:
simply have a switch somewhere inside a listener of either a ComboBox or an OptionGroup (for radio buttons) to make a the following ChartOptions static method call, e.g.:
ChartOptions.get().setTheme(new VaadinTheme())
then
ChartOptions.get().setTheme(new SkiesTheme())
etc.
there's also GridTheme(); GrayTheme() and HighChartsDefaultTheme(); you can even extend the base theme to create your own theme (look that up in the Book of Vaadin).
Since Vaadin 7.3 you can use UI#setTheme()
In Vaadin 7 and higher Versions we have an Annotation called #Theme(yourThemeName)
based on the Theme name which you give here it will redirect to that specific .scss Style.This annotation is called before the Init method is called.
I've built a log-in composite that I am displaying in my application entry-point to the user. Upon entry of the username and password, I am sending the username and password to the server via a RemoteService and will receive back an object containing the ClientSession. If the ClientSession is a valid object (recognised username and password), I wish to display the main application panel otherwise I want to display the login dialog again (with an error message).
My question is, that during the async call to the server, how to I mask the screen so that the user cannot click anything whilst the Session is obtained from the server?
I know that the login should be fast, but the Session object contains a lot of Client Side cached values for the current user that is used to generate the main panel. This may take a fraction of a second or up to 5 seconds (I can't control the speed of the underlying infrastructure unfortunately) so I want to mask the screen until a timeout is reached then allow the user to try again.
I have done this exact operation before using GWT Ext, but vanilla GWT seems to have a lot less samples unfortunately.
Thanks
Chris
The GWT class PopupPanel has an optional "glass panel" that blocks interaction with the page underneath.
final PopupPanel popup = new PopupPanel(false, true); // Create a modal dialog box that will not auto-hide
popup.add(new Label("Please wait"));
popup.setGlassEnabled(true); // Enable the glass panel
popup.center(); // Center the popup and make it visible
You might want to check out GlassPanel from the GWT Incubator project. AFAICT it's not perfect, but should be of some help nevertheless ;)
You can also use a dialog box for this purpose.
Here is the code how to use it.
public class NTMaskAlert extends DialogBox {
private String displayText;
private String message;
private static NTMaskAlert alert;
Label lable;
private NTMaskAlert(String text) {
setText(text);
setWidget(new Image(GWT.getModuleBaseURL()
+ "/images/ajax-loader_1.gif"));
setGlassEnabled(true);
setAnimationEnabled(true);
super.show();
super.center();
WorkFlowSessionFactory.putValue(WorkFlowSesisonKey.MASKING_PANEL, this);
}
public static void mask(String text) {
if (text != null)
new NTMaskAlert(text);
else
new NTMaskAlert("Processing");
}
public static void unMask() {
NTMaskAlert alert = (NTMaskAlert) WorkFlowSessionFactory
.getValue(WorkFlowSesisonKey.MASKING_PANEL);
if (alert != null) {
alert.hide();
alert = null;
}
}
public void setDisplayText(String displayText) {
this.displayText = displayText;
alert.setText(displayText);
}
public String getDisplayText() {
return displayText;
}
public void setMessage(String message) {
this.message = message;
lable.setText(message);
}
public String getMessage() {
return message;
}
}
Use static mask and unmask method for operations.
This is my solution:
public class CustomPopupPanel extends PopupPanel {
private Label label = new Label();
public CustomPopupPanel() {
super(false, true); // Create a modal dialog box that will not auto-hide
super.setGlassEnabled(true); // Enable the glass panel
super.add(label); // Add the widget label into the panel
}
public CustomPopupPanel(String text) {
this();
this.mask(text);
}
public final void mask(String text) {
label.setText(text);
super.center(); // Center the popup and make it visible
}
public void unmask() {
super.hide(); // Hide the popup
}
}