Class WDialog

Direct Known Subclasses:
PasswordPromptDialog, WMessageBox

public class WDialog
extends WPopupWidget
A WDialog shows a dialog.

By default, the dialog is modal. A modal window blocks the user interface, and does not allow the user to interact with any other part of the user interface until the dialog is closed (this is enforced at the server side, so you may rely on this behavior).

A modal dialog can be instantiated synchronously or asynchronously. A non-modal dialog can only be instantiated asynchronously.

When using a dialog asynchronously, there is no API call that waits for the dialog to be closed. Then, the usage is similar to instantiating any other widget. The dialog may be closed by calling accept(), reject() or done() (or connecting a signal to one of these methods). This will hide the dialog and emit the finished() signal, which you then can listen for to process the dialog result and delete the dialog. Unlike other widgets, a dialog does not need to be added to a parent widget, but is hidden by default. You must use the method WWidget.show() or setHidden() to show the dialog.

The synchronous use of a dialog involves a call to exec() which will block (suspend the thread) until the dialog window is closed, and return the dialog result. Events within dialog are handled using a so-called recursive event loop. Typically, an OK button will be connected to accept(), and in some cases a StandardButton.Cancel button to reject(). This solution has the drawback that it is not scalable to many concurrent sessions, since for every session with a recursive event loop, a thread is locked until exec() returns. A thread that is locked by a recursive event loop cannot be used to process requests from another sessions. When all threads in the threadpool are locked in recursive event loops, the server will be unresponsive to requests from any other session. In practical terms, this means you must not use exec(), unless your application will never be used by more concurrent users than the amount of threads in your threadpool (like on some intranets or extranets). Using exec() is not supported from outside the regular event loop (i.e. when taking a lock on a session using WApplication.getUpdateLock() or by posting an event using WServer::post()). This functionality is only available on Servlet 3.0 compatible servlet containers. Use setModal() to create a non-modal dialog. A non-modal dialog does not block the underlying user interface: the user must not first deal with the dialog before interacting with the rest of the user interface.

Contents for the dialog is defined by adding it to the getContents() widget.

This dialog looks like this (using the default css themes):

A simple custom dialog (default)

A simple custom dialog (polished)

Note: For the dialog (or rather, the silkscreen covering the user interface below) to render properly in IE, the "html body" margin is set to 0 (if it wasn't already).

  • Constructor Details

    • WDialog

      public WDialog()
      Constructs a new dialog.

      Unlike other widgets, the dialog does not require a parent container since it is a top-level widget.

    • WDialog

      public WDialog​(java.lang.CharSequence windowTitle)
      Constructs a dialog with a given window title.

      Unlike other widgets, the dialog does not require a parent container since it is a top-level widget.

  • Method Details

    • remove

      public void remove()
      Deletes a dialog.
      Overrides:
      remove in class WPopupWidget
      See Also:
      WWidget.removeWidget(WWidget widget)
    • setWindowTitle

      public void setWindowTitle​(java.lang.CharSequence windowTitle)
      Sets the dialog window title.

      The window title is displayed in the title bar.

      See Also:
      setTitleBarEnabled(boolean enable)
    • getWindowTitle

      public WString getWindowTitle()
      Returns the dialog window title.

      See Also:
      setWindowTitle(CharSequence windowTitle)
    • setTitleBarEnabled

      public void setTitleBarEnabled​(boolean enable)
      Enables or disables the title bar.

      The titlebar is enabled by default.

    • isTitleBarEnabled

      public boolean isTitleBarEnabled()
      Returns whether the title bar is enabled.

      See Also:
      setTitleBarEnabled(boolean enable)
    • getTitleBar

      public WContainerWidget getTitleBar()
      Returns the dialog title bar container.

      The title bar contains a single text that contains the caption. You may customize the title bar by for example adding other content.

    • getContents

      public WContainerWidget getContents()
      Returns the dialog contents container.

      Content to the dialog window may be added to this container widget.

    • getFooter

      public WContainerWidget getFooter()
      Returns the dialog footer container.

      This is an optional section which is typically used for buttons.

    • exec

      public DialogCode exec​(WAnimation animation)
      Executes the dialog in a recursive event loop.

      Executes the dialog synchronously. This blocks the current thread of execution until one of done(), accept() or reject() is called.

      Warning: using exec() does not scale to many concurrent sessions, since the thread is locked until exec returns, so the entire server will be unresponsive when the thread pool is exhausted.

      This functionality is only available on Servlet 3.0 compatible servlet containers.

      See Also:
      done(DialogCode result), accept(), reject()
    • exec

      public final DialogCode exec()
      Executes the dialog in a recursive event loop.

      Returns exec(new WAnimation())

    • done

      public void done​(DialogCode result)
      Stops the dialog.

      Sets the dialog result, and emits the finished() signal.

      See Also:
      finished(), getResult()
    • accept

      public void accept()
      Closes the dialog, with result is Accepted.

      See Also:
      done(DialogCode result), reject()
    • reject

      public void reject()
      Closes the dialog, with result is Rejected.

      See Also:
      done(DialogCode result), accept()
    • rejectWhenEscapePressed

      public void rejectWhenEscapePressed​(boolean enable)
      Lets pressing the escape key reject the dialog.

      Before JWt 3.1.5, pressing escape automatically rejected the dialog. Since 3.1.4 this behaviour is no longer the default since it may interfere with other functionality in the dialog. Use this method to enable this behaviour.

      See Also:
      reject()
    • rejectWhenEscapePressed

      public final void rejectWhenEscapePressed()
      Lets pressing the escape key reject the dialog.

      Calls rejectWhenEscapePressed(true)

    • finished

      public Signal1<DialogCode> finished()
      Signal emitted when the dialog is closed.

      See Also:
      done(DialogCode result), accept(), reject()
    • getResult

      public DialogCode getResult()
      Returns the result that was set for this dialog.

      See Also:
      done(DialogCode result)
    • setModal

      public void setModal​(boolean modal)
      Sets whether the dialog is modal.

      A modal dialog will block the underlying user interface. A modal dialog can be shown synchronously or asynchronously. A non-modal dialog can only be shown asynchronously.

      By default a dialog is modal.

    • isModal

      public boolean isModal()
      Returns whether the dialog is modal.

      See Also:
      setModal(boolean modal)
    • setResizable

      public void setResizable​(boolean resizable)
      Adds a resize handle to the dialog.

      The resize handle is shown in the bottom right corner of the dialog, and allows the user to resize the dialog (but not smaller than the content allows).

      This also sets the minimum width and height to WLength.Auto to use the initial width and height as minimum sizes. You may want to provide other values for minimum width and height to allow the dialog to be reduced in size.

      The default value is false.

      See Also:
      setMinimumSize(WLength width, WLength height), setMaximumSize(WLength width, WLength height)
    • isResizable

      public boolean isResizable()
      Returns whether the dialog has a resize handle.

      See Also:
      setResizable(boolean resizable)
    • setMovable

      public void setMovable​(boolean movable)
      Allows the dialog to be moved.

      The dialog can be moved by grabbing the titlebar.

      The default value is true.

    • isMovable

      public boolean isMovable()
      Returns whether the dialog can be moved.

      See Also:
      setMovable(boolean movable)
    • setClosable

      public void setClosable​(boolean closable)
      Adds a close button to the titlebar.

      The close button is shown in the title bar. Clicking the close button will reject the dialog.

    • isClosable

      public boolean isClosable()
      Returns whether the dialog can be closed.
    • setAutoFocus

      public void setAutoFocus​(boolean enable)
      Set focus on the first widget in the dialog.

      Autofocus is enabled by default. If a widget inside of this dialog already has focus, the focus will not be changed.

    • setHidden

      public void setHidden​(boolean hidden, WAnimation animation)
      Description copied from class: WWidget
      Hides or shows the widget.

      Hides or show the widget (including all its descendant widgets). When setting hidden = false, this widget and all descendant widgets that are not hidden will be shown. A widget is only visible if it and all its ancestors in the widget tree are visible, which may be checked using isVisible().

      Overrides:
      setHidden in class WPopupWidget
    • positionAt

      public void positionAt​(WWidget widget, Orientation orientation)
      Description copied from class: WWidget
      Positions a widget next to another widget.

      Positions this absolutely positioned widget next to another widget. Both widgets must be visible (including all their ancestors). The current widget is shown automatically if needed.

      When orientation = Orientation.Vertical, the widget is displayed below the other widget (or above in case there is not enough room below). It is aligned so that the left edges align (or the right edges if there is not enough room to the right).

      Conversely, when orientation = Orientation.Horizontal, the widget is displayed to the right of the other widget (or to the left in case there is not enough room to the right). It is aligned so that the top edges align (or the bottom edges if there is not enough room below).

      Note: This only works if JavaScript is available.

      Overrides:
      positionAt in class WWidget
    • positionAt

      public void positionAt​(WMouseEvent ev)
      Set the position of the widget at the mouse position.
    • raiseToFront

      public void raiseToFront()
      Raises this dialog to be the top-most dialog.
    • setMinimumSize

      public void setMinimumSize​(WLength width, WLength height)
      Description copied from class: WWidget
      Sets a minimum size.

      Specifies a minimum size for this widget, setting CSS min-width and min-height properties.

      The default minimum width and height is 0. The special value WLength.Auto indicates that the initial width is used as minimum size. A LengthUnit.Percentage size should not be used, as this is (in virtually all cases) undefined behaviour.

      When the widget is inserted in a layout manager, then the minimum size will be taken into account.

      Overrides:
      setMinimumSize in class WCompositeWidget
      See Also:
      WWidget.resize(WLength width, WLength height), WWidget.getMinimumWidth(), WWidget.getMinimumHeight()
    • setMaximumSize

      public void setMaximumSize​(WLength width, WLength height)
      Description copied from class: WWidget
      Sets a maximum size.

      Specifies a maximum size for this widget, setting CSS max-width and max-height properties.

      The default the maximum width and height are WLength.Auto, indicating no maximum size. A LengthUnit.Percentage size should not be used, as this is (in virtually all cases) undefined behaviour.

      When the widget is a container widget that contains a layout manager, then setting a maximum size will have the effect of letting the size of the container to reflect the preferred size of the contents (rather than constraining the size of the children based on the size of the container), up to the specified maximum size.

      Overrides:
      setMaximumSize in class WCompositeWidget
      See Also:
      WWidget.resize(WLength width, WLength height), WWidget.setMinimumSize(WLength width, WLength height)
    • resized

      public JSignal2<java.lang.Integer,​java.lang.Integer> resized()
      Signal emitted when the dialog is being resized by the user.

      The information passed are the new width and height.

      See Also:
      setResizable(boolean resizable)
    • moved

      public JSignal2<java.lang.Integer,​java.lang.Integer> moved()
      Signal emitted when the dialog is being moved by the user.

      The information passed are the new x and y position (relative to the wietdow).

    • keyWentDown

      public EventSignal1<WKeyEvent> keyWentDown()
      Event signal emitted when a keyboard key is pushed down.

      The event will be triggered if nothing in the WDialog has focus

    • keyPressed

      public EventSignal1<WKeyEvent> keyPressed()
      Event signal emitted when a "character" was entered.

      The event will be triggered if nothing in the WDialog has focus

    • keyWentUp

      public EventSignal1<WKeyEvent> keyWentUp()
      Event signal emitted when a keyboard key is released.

      The event will be triggered if nothing in the WDialog has focus

    • enterPressed

      public EventSignal enterPressed()
      Event signal emitted when enter was pressed.

      The event will be triggered if nothing in the WDialog has focus

    • escapePressed

      public EventSignal escapePressed()
      Event signal emitted when escape was pressed.

      The event will be triggered if nothing in the WDialog has focus

    • touchStarted

      public EventSignal1<WTouchEvent> touchStarted()
      Event signal emitted when a finger is placed on the screen.
    • touchEnded

      public EventSignal1<WTouchEvent> touchEnded()
      Event signal emitted when a finger is removed from the screen.
    • touchMoved

      public EventSignal1<WTouchEvent> touchMoved()
      Event signal emitted when a finger, which is already placed on the screen, is moved across the screen.
    • render

      protected void render​(java.util.EnumSet<RenderFlag> flags)
      Description copied from class: WWidget
      Renders the widget.

      This function renders the widget (or an update for the widget), after this has been scheduled using scheduleRender().

      The default implementation will render the widget by serializing changes to JavaScript and HTML. You may want to reimplement this widget if you have been postponing some of the layout / rendering implementation until the latest moment possible. In that case you should make sure you call the base implementation however.

      Overrides:
      render in class WPopupWidget
    • onPathChange

      protected void onPathChange()
      Overrides:
      onPathChange in class WPopupWidget