Tracker

Instances of this class implement rubber banding rectangles that are drawn onto a parent <code>Composite</code> or <code>Display</code>. These rectangles can be specified to respond to mouse and key events by either moving or resizing themselves accordingly. Trackers are typically used to represent window geometries in a lightweight manner.

<dl> <dt>Styles:</dt> <dd>LEFT, RIGHT, UP, DOWN, RESIZE</dd> <dt>Events:</dt> <dd>Move, Resize</dd> </dl> Note: Rectangle move behavior is assumed unless RESIZE is specified. IMPORTANT: This class is not intended to be subclassed.

@see <a href="http://www.eclipse.org/swt/snippets/#tracker">Tracker snippets</a> @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>

class Tracker : Widget {

Composite parent;

Cursor cursor;

GdkCursor* lastCursor;

GdkDrawable* window;

bool tracking;

bool cancelled;

bool grabbed;

bool stippled;

Rectangle[] rectangles;

Rectangle[] proportions;

Rectangle bounds;

int cursorOrientation;

int oldX;

int oldY;

int STEPSIZE_SMALL;

int STEPSIZE_LARGE;

this(Composite parent, int style);

this(Display display, int style);

void addControlListener(ControlListener listener);

void addKeyListener(KeyListener listener);

void close();

Rectangle[] getRectangles();

bool getStippled();

bool open();

void removeControlListener(ControlListener listener);

void removeKeyListener(KeyListener listener);

void setCursor(Cursor value);

void setRectangles(Rectangle[] rectangles);

void setStippled(bool stippled);

}

Constructors

this this(Composite parent, int style): Constructs a new instance of this class given its parent and a style value describing its behavior and appearance. The style value is either one of the style constants defined in class <code>SWT</code> which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the <code>int</code> "|" operator) two or more of those <code>SWT</code> style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.
this this(Display display, int style): Constructs a new instance of this class given the display to create it on and a style value describing its behavior and appearance. The style value is either one of the style constants defined in class <code>SWT</code> which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the <code>int</code> "|" operator) two or more of those <code>SWT</code> style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses. Note: Currently, null can be passed in for the display argument. This has the effect of creating the tracker on the currently active display if there is one. If there is no current display, the tracker is created on a "default" display. Passing in null as the display argument is not considered to be good coding style, and may not be supported in a future release of SWT.

Members

Functions

addControlListener void addControlListener(ControlListener listener): Adds the listener to the collection of listeners who will be notified when the control is moved or resized, by sending it one of the messages defined in the <code>ControlListener</code> interface.
addKeyListener void addKeyListener(KeyListener listener): Adds the listener to the collection of listeners who will be notified when keys are pressed and released on the system keyboard, by sending it one of the messages defined in the <code>KeyListener</code> interface.
close void close(): Stops displaying the tracker rectangles. Note that this is not considered to be a cancelation by the user.
getRectangles Rectangle[] getRectangles(): Returns the bounds that are being drawn, expressed relative to the parent widget. If the parent is a <code>Display</code> then these are screen coordinates.
getStippled bool getStippled(): Returns <code>true</code> if the rectangles are drawn with a stippled line, <code>false</code> otherwise.
open bool open(): Displays the Tracker rectangles for manipulation by the user. Returns when the user has either finished manipulating the rectangles or has cancelled the Tracker.
removeControlListener void removeControlListener(ControlListener listener): Removes the listener from the collection of listeners who will be notified when the control is moved or resized.
removeKeyListener void removeKeyListener(KeyListener listener): Removes the listener from the collection of listeners who will be notified when keys are pressed and released on the system keyboard.
setCursor void setCursor(Cursor value): Sets the <code>Cursor</code> of the Tracker. If this cursor is <code>null</code> then the cursor reverts to the default.
setRectangles void setRectangles(Rectangle[] rectangles): Specifies the rectangles that should be drawn, expressed relative to the parent widget. If the parent is a Display then these are screen coordinates.
setStippled void setStippled(bool stippled): Changes the appearance of the line used to draw the rectangles.

Inherited Members

handle GtkWidget* handle;: the handle to the OS resource (Warning: This field is platform dependent) IMPORTANT: This field is not part of the SWT public API. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms and should never be accessed from application code.
addListener void addListener(int eventType, Listener listener): Adds the listener to the collection of listeners who will be notified when an event of the given type occurs. When the event does occur in the widget, the listener is notified by sending it the <code>handleEvent()</code> message. The event type is one of the event constants defined in class <code>SWT</code>.
addDisposeListener void addDisposeListener(DisposeListener listener): Adds the listener to the collection of listeners who will be notified when the widget is disposed. When the widget is disposed, the listener is notified by sending it the <code>widgetDisposed()</code> message.
checkParent void checkParent(Widget parent): Throws an exception if the specified widget can not be used as a parent for the receiver.
checkSubclass void checkSubclass(): Checks that this class can be subclassed. The SWT class library is intended to be subclassed only at specific, controlled points (most notably, <code>Composite</code> and <code>Canvas</code> when implementing new widgets). This method enforces this rule unless it is overridden. IMPORTANT: By providing an implementation of this method that allows a subclass of a class which does not normally allow subclassing to be created, the implementer agrees to be fully responsible for the fact that any such subclass will likely fail between SWT releases and will be strongly platform specific. No support is provided for user-written classes which are implemented in this fashion. The ability to subclass outside of the allowed SWT classes is intended purely to enable those not on the SWT development team to implement patches in order to get around specific limitations in advance of when those limitations can be addressed by the team. Subclassing should not be attempted without an intimate and detailed understanding of the hierarchy.
checkWidget void checkWidget(): Throws an <code>SWTException</code> if the receiver can not be accessed by the caller. This may include both checks on the state of the receiver and more generally on the entire execution context. This method should be called by widget implementors to enforce the standard SWT invariants. Currently, it is an error to invoke any method (other than <code>isDisposed()</code>) on a widget that has had its <code>dispose()</code> method called. It is also an error to call widget methods from any thread that is different from the thread that created the widget. In future releases of SWT, there may be more or fewer error checks and exceptions may be thrown for different reasons.
dispose void dispose(): Disposes of the operating system resources associated with the receiver and all its descendants. After this method has been invoked, the receiver and all descendants will answer <code>true</code> when sent the message <code>isDisposed()</code>. Any internal connections between the widgets in the tree will have been removed to facilitate garbage collection. NOTE: This method is not called recursively on the descendants of the receiver. This means that, widget implementers can not detect when a widget is being disposed of by re-implementing this method, but should instead listen for the <code>Dispose</code> event.
getData Object getData(): Returns the application defined widget data associated with the receiver, or null if it has not been set. The widget data is a single, unnamed field that is stored with every widget. Applications may put arbitrary objects in this field. If the object stored in the widget data needs to be notified when the widget is disposed of, it is the application's responsibility to hook the Dispose event on the widget and do so.
getData Object getData(String key): Returns the application defined property of the receiver with the specified name, or null if it has not been set. Applications may have associated arbitrary objects with the receiver in this fashion. If the objects stored in the properties need to be notified when the widget is disposed of, it is the application's responsibility to hook the Dispose event on the widget and do so.
getDisplay Display getDisplay(): Returns the <code>Display</code> that is associated with the receiver. A widget's display is either provided when it is created (for example, top level <code>Shell</code>s) or is the same as its parent's display.
getListeners Listener[] getListeners(int eventType): Returns an array of listeners who will be notified when an event of the given type occurs. The event type is one of the event constants defined in class <code>SWT</code>.
getStyle int getStyle(): Returns the receiver's style information. Note that the value which is returned by this method may not match the value which was provided to the constructor when the receiver was created. This can occur when the underlying operating system does not support a particular combination of requested styles. For example, if the platform widget used to implement a particular SWT widget always has scroll bars, the result of calling this method would always have the <code>SWT.H_SCROLL</code> and <code>SWT.V_SCROLL</code> bits set.
isDisposed bool isDisposed(): Returns <code>true</code> if the widget has been disposed, and <code>false</code> otherwise. This method gets the dispose state for the widget. When a widget has been disposed, it is an error to invoke any other method using the widget.
isListening bool isListening(int eventType): Returns <code>true</code> if there are any listeners for the specified event type associated with the receiver, and <code>false</code> otherwise. The event type is one of the event constants defined in class <code>SWT</code>.
notifyListeners void notifyListeners(int eventType, Event event): Notifies all of the receiver's listeners for events of the given type that one such event has occurred by invoking their <code>handleEvent()</code> method. The event type is one of the event constants defined in class <code>SWT</code>.
removeListener void removeListener(int eventType, Listener handler): Removes the listener from the collection of listeners who will be notified when an event of the given type occurs. The event type is one of the event constants defined in class <code>SWT</code>.
removeListener void removeListener(int eventType, SWTEventListener handler): Removes the listener from the collection of listeners who will be notified when an event of the given type occurs. IMPORTANT: This method is not part of the SWT public API. It is marked public only so that it can be shared within the packages provided by SWT. It should never be referenced from application code.
removeDisposeListener void removeDisposeListener(DisposeListener listener): Removes the listener from the collection of listeners who will be notified when the widget is disposed.
setData void setData(Object data): Sets the application defined widget data associated with the receiver to be the argument. The widget data is a single, unnamed field that is stored with every widget. Applications may put arbitrary objects in this field. If the object stored in the widget data needs to be notified when the widget is disposed of, it is the application's responsibility to hook the Dispose event on the widget and do so.
setData void setData(String key, Object value): Sets the application defined property of the receiver with the specified name to the given value. Applications may associate arbitrary objects with the receiver in this fashion. If the objects stored in the properties need to be notified when the widget is disposed of, it is the application's responsibility to hook the Dispose event on the widget and do so.
toString String toString(): Returns a string containing a concise, human-readable description of the receiver.

Tracker

Constructors

Members

Functions

Inherited Members

From Widget

Meta

Source