Java tutorial
/* * InlineToolbarButton.java * * Copyright (C) 2009-12 by RStudio, Inc. * * Unless you have received this program directly from RStudio pursuant * to the terms of a commercial license agreement with RStudio, then * this program is licensed to you under the terms of version 3 of the * GNU Affero General Public License. This program is distributed WITHOUT * ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT, * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the * AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details. * */ package org.rstudio.core.client.widget; import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.Scheduler; import com.google.gwt.core.client.Scheduler.ScheduledCommand; import com.google.gwt.dom.client.Document; import com.google.gwt.dom.client.NativeEvent; import com.google.gwt.event.dom.client.*; import com.google.gwt.event.logical.shared.CloseEvent; import com.google.gwt.event.logical.shared.CloseHandler; import com.google.gwt.event.shared.HandlerManager; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.event.shared.HasHandlers; import com.google.gwt.resources.client.ImageResource; import com.google.gwt.uibinder.client.UiBinder; import com.google.gwt.uibinder.client.UiConstructor; import com.google.gwt.uibinder.client.UiField; import com.google.gwt.user.client.ui.Composite; import com.google.gwt.user.client.ui.Image; import com.google.gwt.user.client.ui.PopupPanel; import com.google.gwt.user.client.ui.Widget; import com.google.gwt.user.client.ui.PopupPanel.PositionCallback; import org.rstudio.core.client.StringUtil; public class InlineToolbarButton extends Composite implements HasButtonMethods { private class SimpleHasHandlers extends HandlerManager implements HasHandlers { private SimpleHasHandlers() { super(null); } } interface Binder extends UiBinder<Widget, InlineToolbarButton> { } @UiConstructor public InlineToolbarButton(ImageResource icon, String label, String description) { icon_ = new Image(icon); label_ = new SpanLabel(label, false); zeroHeightPanel_ = new ZeroHeightPanel(icon.getWidth(), icon.getHeight(), 4); if (StringUtil.isNullOrEmpty(label)) label_.setVisible(false); initWidget(GWT.<Binder>create(Binder.class).createAndBindUi(this)); setTitle(description); } public void setLabel(String text) { label_.setText(text); label_.setVisible(!StringUtil.isNullOrEmpty(text)); } public void setMenu(final ToolbarPopupMenu menu) { /* * We want clicks on this button to toggle the visibility of the menu, * as well as having the menu auto-hide itself as it normally does. * It's necessary to manually track the visibility (menuShowing) because * in the case where the menu is showing, clicking on this button first * causes the menu to auto-hide and then our mouseDown handler is called * (so we can't rely on menu.isShowing(), it'll always be false by the * time you get into the mousedown handler). */ final boolean[] menuShowing = new boolean[1]; addDomHandler(new MouseDownHandler() { public void onMouseDown(MouseDownEvent event) { event.preventDefault(); event.stopPropagation(); if (menuShowing[0]) { menu.hide(); } else { menu.setPopupPositionAndShow(new PositionCallback() { @Override public void setPosition(int offsetWidth, int offsetHeight) { menu.setPopupPosition(InlineToolbarButton.this.getAbsoluteLeft(), InlineToolbarButton.this.getAbsoluteTop() + InlineToolbarButton.this.getOffsetHeight() + 8 /* toolbar area under botton */); } }); } menuShowing[0] = true; } }, MouseDownEvent.getType()); menu.addCloseHandler(new CloseHandler<PopupPanel>() { public void onClose(CloseEvent<PopupPanel> popupPanelCloseEvent) { Scheduler.get().scheduleDeferred(new ScheduledCommand() { public void execute() { menuShowing[0] = false; } }); } }); } @Override public HandlerRegistration addClickHandler(ClickHandler clickHandler) { /* * When we directly subscribe to this widget's ClickEvent, sometimes the * click gets ignored (inconsistent repro but it happens enough to be * annoying). Doing it this way fixes it. */ hasHandlers_.addHandler(ClickEvent.getType(), clickHandler); final HandlerRegistration mouseDown = addDomHandler(new MouseDownHandler() { public void onMouseDown(MouseDownEvent event) { event.preventDefault(); event.stopPropagation(); down_ = true; } }, MouseDownEvent.getType()); final HandlerRegistration mouseOut = addDomHandler(new MouseOutHandler() { public void onMouseOut(MouseOutEvent event) { event.preventDefault(); event.stopPropagation(); down_ = false; } }, MouseOutEvent.getType()); final HandlerRegistration mouseUp = addDomHandler(new MouseUpHandler() { public void onMouseUp(MouseUpEvent event) { event.preventDefault(); event.stopPropagation(); if (down_) { down_ = false; NativeEvent clickEvent = Document.get().createClickEvent(1, event.getScreenX(), event.getScreenY(), event.getClientX(), event.getClientY(), event.getNativeEvent().getCtrlKey(), event.getNativeEvent().getAltKey(), event.getNativeEvent().getShiftKey(), event.getNativeEvent().getMetaKey()); DomEvent.fireNativeEvent(clickEvent, hasHandlers_); } } }, MouseUpEvent.getType()); return new HandlerRegistration() { public void removeHandler() { mouseDown.removeHandler(); mouseOut.removeHandler(); mouseUp.removeHandler(); } }; } public void click() { NativeEvent clickEvent = Document.get().createClickEvent(1, 0, 0, 0, 0, false, false, false, false); DomEvent.fireNativeEvent(clickEvent, hasHandlers_); } @UiField(provided = true) Image icon_; @UiField(provided = true) SpanLabel label_; @UiField(provided = true) ZeroHeightPanel zeroHeightPanel_; private SimpleHasHandlers hasHandlers_ = new SimpleHasHandlers(); private boolean down_; }