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java.lang.Objectcom.smartgwt.client.util.EventHandler
public class EventHandler
The ISC system provides a predictable cross-browser event-handling mechanism for ISC widgets. Events can be handled both at the page level (i.e., globally), and at the level of individual widgets.
With the exception of a few page-specific events ('load', 'unload', 'idle' and 'resize'), events are processed in the following sequence:
1. The
event is sent to any global (page-level) event handlers. These handlers can cancel further propagation of the event by
returning false. You can register to listen for any of the events linked in the seeAlso section (below) by calling
com.smartgwt.client.util.Page#setEvent
method.
2. If the event occurred on a form element or a link, it is passed on to the browser so that the element will perform its default action. No widget receives the event.
3. If
the event occurred on an enabled widget (but not on a form element or link inside the widget), it is sent to that
widget's event handler, if any. This handler can cancel further propagation of the event by returning false. An
"enabled" widget is any widget that defines an event handler for one of the supported events. Interceptable events are
defined in the com.smartgwt.client..Canvas#methods#events
.
4. The event is "bubbled" up to the widget's parent in the containment hierarchy, if any. Again, the parent's handler for the event can cancel further propagation by returning false. This step is repeated, with the event "bubbling" up through the containment hierarchy, until a top-level widget is reached or the event is explicitly canceled. In brief, the ISC event model offers the best features of browser event models:
Smart GWT libraries will not interfere with native event handling when events occur outside of a target widget. You can therefore have HTML that is not ISC-based on the same page as widget objects that will react to native events as you would expect.
You can use isc.Event as an alias for isc.EventHandler.
Constructor Summary | |
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EventHandler()
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Method Summary | |
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static Boolean |
altKeyDown()
Return true if the alt (option) key is being held down. |
static Boolean |
ctrlKeyDown()
Return true if the control key is being held down. |
static Rectangle |
getDragRect()
During a drag with dragAppearance of either "target" or "outline", returns the page-relative coordinates of whatever element is being dragged. |
static Canvas |
getDragTarget()
Returns the current dragTarget. |
static String |
getKey()
Return the name of the key for the event passed in. |
static String |
getKeyEventCharacter()
Return the character for the current key being pressed. |
static int |
getKeyEventCharacterValue()
Returns the numeric characterValue reported by the browser. |
static Integer |
getMouseDownX()
Return the page-relative X (horizontal) coordinate of an event. |
static Integer |
getMouseDownY()
Return the page-relative Y (vertical) coordinate of an event. |
static Canvas |
getTarget()
Return the canvas that is the target of the mouse event. |
static int |
getWheelDelta()
Applies to Canvas.addMouseWheelHandler(com.smartgwt.client.widgets.events.MouseWheelHandler) events only. |
static int |
getX()
Return the page-relative X (horizontal) coordinate of an event. |
static int |
getY()
Return the page-relative Y (vertical) coordinate of an event. |
static Boolean |
leftButtonDown()
Returns true if the left mouse button is being pressed. |
static Boolean |
rightButtonDown()
Returns true if the right mouse button is being pressed. |
static void |
setDragTracker(String html)
Set the HTML for the drag tracker that follows the mouse during a drag and drop interaction. |
static void |
setDragTracker(String html,
int newWidth,
int newHeight,
int offsetX,
int offsetY)
Set the HTML for the drag tracker that follows the mouse during a drag and drop interaction. |
static Boolean |
shiftKeyDown()
Return true if the shift key is being held down. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public EventHandler()
Method Detail |
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public static int getWheelDelta()
Canvas.addMouseWheelHandler(com.smartgwt.client.widgets.events.MouseWheelHandler)
events only. Returns an integer indicating
how far the mouse wheel was rotated. This value will be positive if the user scrolled the mousewheel forward or up, or
negative if scrolled in the other direction and will be a multiple of 1 where 1 indicates the smallest possible rotation
of the wheel.
public static Canvas getTarget()
public static Canvas getDragTarget()
public static int getX()
public static int getY()
public static Boolean leftButtonDown()
public static Boolean rightButtonDown()
public static int getKeyEventCharacterValue()
public static String getKeyEventCharacter()
public static Boolean shiftKeyDown()
public static Boolean ctrlKeyDown()
public static Boolean altKeyDown()
public static void setDragTracker(String html)
Your canvas can use this routine to set the drag tracker to whatever HTML you want like so:
dragStart : function () { isc.EventHandler.setDragTracker('Your contents here'); }
html
- HTML for the trackerpublic static void setDragTracker(String html, int newWidth, int newHeight, int offsetX, int offsetY)
Your canvas can use this routine to set the drag tracker to whatever HTML you want like so:
dragStart : function () { isc.EventHandler.setDragTracker('Your contents here'); }
html
- HTML for the trackernewWidth
- new width for the trackernewHeight
- new height for the trackeroffsetX
- x-offset for the trackeroffsetY
- y-offset for the trackerpublic static Rectangle getDragRect()
public static Integer getMouseDownX()
public static Integer getMouseDownY()
public static String getKey()
Strings to identify the various keys on the keyboard. For alpha keys, the single (uppercase) character value is used, such as "Q" For Numeric keys, the number is used as in a single character string, like "1" Function keys are identified as "f1" - "f12" Non alpha-numeric character keys (such as the key for "[" / "{") are identified by their unmodified character value (the value obtained by hitting the key without holding shift down), by default - exceptions are listed below. Additional key names: - Space - Tab - Enter - Escape - Backspace - Insert - Delete - Arrow_Up - Arrow_Down - Arrow_Left - Arrow_Right - Home - End - Page_Up - Page_Down - Shift - Ctrl - Alt [Note: Some keys may not be available for capture on every platform]
KeyNames
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