diff options
| -rw-r--r-- | client/src/com/vaadin/client/ui/TouchScrollDelegate.java | 68 |
1 files changed, 61 insertions, 7 deletions
diff --git a/client/src/com/vaadin/client/ui/TouchScrollDelegate.java b/client/src/com/vaadin/client/ui/TouchScrollDelegate.java index 45bd2616f3..9d7e435339 100644 --- a/client/src/com/vaadin/client/ui/TouchScrollDelegate.java +++ b/client/src/com/vaadin/client/ui/TouchScrollDelegate.java @@ -21,6 +21,7 @@ import java.util.HashSet; import com.google.gwt.animation.client.Animation; import com.google.gwt.core.client.Duration; +import com.google.gwt.core.client.GWT; import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.NativeEvent; import com.google.gwt.dom.client.Node; @@ -111,20 +112,51 @@ public class TouchScrollDelegate implements NativePreviewHandler { private static final String SCROLLABLE_CLASSNAME = "v-scrollable"; - private final TouchScrollDelegate delegate; + private TouchScrollDelegate delegate; private final boolean requiresDelegate = BrowserInfo.get() .requiresTouchScrollDelegate(); + private Widget widget; + /** - * Constructs a scroll handler for the given widget. + * Constructs a scroll handler. You must call + * {@link #init(Widget, Element...)} before using the scroll handler. + */ + public TouchScrollHandler() { + + } + + /** + * Attaches the scroll handler to the widget. This method must be called + * before calling any other methods in this class. * * @param widget * The widget that contains scrollable elements * @param scrollables * The elements of the widget that should be scrollable. + * + * @deprecated Use {@link GWT#create(Class)} and + * {@link #init(Widget, Element...)} instead of this + * constructor to enable overriding. */ + @Deprecated public TouchScrollHandler(Widget widget, Element... scrollables) { - if (requiresDelegate) { + this(); + init(widget, scrollables); + } + + /** + * Attaches the scroll handler to the widget. This method must be called + * once before calling any other method in this class. + * + * @param widget + * The widget that contains scrollable elements + * @param scrollables + * The elements of the widget that should be scrollable. + */ + public void init(Widget widget, Element... scrollables) { + this.widget = widget; + if (requiresDelegate()) { delegate = new TouchScrollDelegate(); widget.addDomHandler(this, TouchStartEvent.getType()); } else { @@ -150,7 +182,7 @@ public class TouchScrollDelegate implements NativePreviewHandler { */ public void addElement(Element scrollable) { scrollable.addClassName(SCROLLABLE_CLASSNAME); - if (requiresDelegate) { + if (requiresDelegate()) { delegate.scrollableElements.add(scrollable); } } @@ -162,7 +194,7 @@ public class TouchScrollDelegate implements NativePreviewHandler { */ public void removeElement(Element scrollable) { scrollable.removeClassName(SCROLLABLE_CLASSNAME); - if (requiresDelegate) { + if (requiresDelegate()) { delegate.scrollableElements.remove(scrollable); } } @@ -175,7 +207,7 @@ public class TouchScrollDelegate implements NativePreviewHandler { * The elements that should be scrollable */ public void setElements(Element... scrollables) { - if (requiresDelegate) { + if (requiresDelegate()) { for (Element e : delegate.scrollableElements) { e.removeClassName(SCROLLABLE_CLASSNAME); } @@ -185,6 +217,26 @@ public class TouchScrollDelegate implements NativePreviewHandler { addElement(e); } } + + /** + * Checks if a delegate for scrolling is required or if the native + * scrolling of the device should be used. By default, relies on + * {@link BrowserInfo#requiresTouchScrollDelegate()}, override to change + * the behavior. + * + * @return true if a Javascript delegate should be used for scrolling, + * false to use the native scrolling of the device + */ + protected boolean requiresDelegate() { + return requiresDelegate; + } + + /** + * @return The widget this {@link TouchScrollHandler} is connected to. + */ + protected Widget getWidget() { + return widget; + } } /** @@ -199,7 +251,9 @@ public class TouchScrollDelegate implements NativePreviewHandler { */ public static TouchScrollHandler enableTouchScrolling(Widget widget, Element... scrollables) { - return new TouchScrollHandler(widget, scrollables); + TouchScrollHandler handler = GWT.create(TouchScrollHandler.class); + handler.init(widget, scrollables); + return handler; } public TouchScrollDelegate(Element... elements) { |