com.google.gwt.user.client.ui.TabBar Maven / Gradle / Ivy
/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.user.client.ui;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.HasAllKeyHandlers;
import com.google.gwt.event.dom.client.HasClickHandlers;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.event.logical.shared.BeforeSelectionEvent;
import com.google.gwt.event.logical.shared.BeforeSelectionHandler;
import com.google.gwt.event.logical.shared.HasBeforeSelectionHandlers;
import com.google.gwt.event.logical.shared.HasSelectionHandlers;
import com.google.gwt.event.logical.shared.SelectionEvent;
import com.google.gwt.event.logical.shared.SelectionHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Event;
/**
* A horizontal bar of folder-style tabs, most commonly used as part of a
* {@link com.google.gwt.user.client.ui.TabPanel}.
*
* 
*
* CSS Style Rules
*
* - .gwt-TabBar { the tab bar itself }
* - .gwt-TabBar .gwt-TabBarFirst { the left edge of the bar }
* - .gwt-TabBar .gwt-TabBarFirst-wrapper { table cell around the left edge }
*
* - .gwt-TabBar .gwt-TabBarRest { the right edge of the bar }
* - .gwt-TabBar .gwt-TabBarRest-wrapper { table cell around the right edge }
*
* - .gwt-TabBar .gwt-TabBarItem { unselected tabs }
* - .gwt-TabBar .gwt-TabBarItem-wrapper { table cell around tab }
* - .gwt-TabBar .gwt-TabBarItem-selected { additional style for selected
*
*
Example
* {@example com.google.gwt.examples.TabBarExample}
*
*/
@SuppressWarnings("deprecation")
public class TabBar extends Composite implements SourcesTabEvents,
HasBeforeSelectionHandlers, HasSelectionHandlers,
ClickListener, KeyboardListener {
/**
* Set of characteristic interfaces supported by {@link TabBar} tabs.
*
* Note that this set might expand over time, so implement this interface at
* your own risk.
*/
public interface Tab extends HasAllKeyHandlers, HasClickHandlers, HasWordWrap {
/**
* Check if the underlying widget implements {@link HasWordWrap}.
*
* @return true if the widget implements {@link HasWordWrap}
*/
boolean hasWordWrap();
}
/**
* ClickDelegatePanel decorates any widget with the minimal
* amount of machinery to receive clicks for delegation to the parent.
* {@link SourcesClickEvents} is not implemented due to the fact that only a
* single observer is needed.
*/
private class ClickDelegatePanel extends Composite implements Tab {
private SimplePanel focusablePanel;
private boolean enabled = true;
ClickDelegatePanel(Widget child) {
focusablePanel = new SimplePanel(FocusPanel.impl.createFocusable());
focusablePanel.setWidget(child);
SimplePanel wrapperWidget = createTabTextWrapper();
if (wrapperWidget == null) {
initWidget(focusablePanel);
} else {
wrapperWidget.setWidget(focusablePanel);
initWidget(wrapperWidget);
}
sinkEvents(Event.ONCLICK | Event.ONKEYDOWN);
}
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addHandler(handler, ClickEvent.getType());
}
public HandlerRegistration addKeyDownHandler(KeyDownHandler handler) {
return addHandler(handler, KeyDownEvent.getType());
}
public HandlerRegistration addKeyPressHandler(KeyPressHandler handler) {
return addDomHandler(handler, KeyPressEvent.getType());
}
public HandlerRegistration addKeyUpHandler(KeyUpHandler handler) {
return addDomHandler(handler, KeyUpEvent.getType());
}
public SimplePanel getFocusablePanel() {
return focusablePanel;
}
public boolean getWordWrap() {
if (hasWordWrap()) {
return ((HasWordWrap) focusablePanel.getWidget()).getWordWrap();
}
throw new UnsupportedOperationException(
"Widget does not implement HasWordWrap");
}
public boolean hasWordWrap() {
return focusablePanel.getWidget() instanceof HasWordWrap;
}
public boolean isEnabled() {
return enabled;
}
@Override
public void onBrowserEvent(Event event) {
if (!enabled) {
return;
}
// No need for call to super.
switch (DOM.eventGetType(event)) {
case Event.ONCLICK:
TabBar.this.selectTabByTabWidget(this);
TabBar.this.onClick(this);
break;
case Event.ONKEYDOWN:
if (((char) DOM.eventGetKeyCode(event)) == KeyCodes.KEY_ENTER) {
TabBar.this.selectTabByTabWidget(this);
}
TabBar.this.onKeyDown(this, (char) event.getKeyCode(),
KeyboardListenerCollection.getKeyboardModifiers(event));
break;
}
super.onBrowserEvent(event);
}
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
public void setWordWrap(boolean wrap) {
if (hasWordWrap()) {
((HasWordWrap) focusablePanel.getWidget()).setWordWrap(wrap);
} else {
throw new UnsupportedOperationException(
"Widget does not implement HasWordWrap");
}
}
}
private static final String STYLENAME_DEFAULT = "gwt-TabBarItem";
private HorizontalPanel panel = new HorizontalPanel();
private Widget selectedTab;
/**
* Creates an empty tab bar.
*/
public TabBar() {
initWidget(panel);
sinkEvents(Event.ONCLICK);
setStyleName("gwt-TabBar");
// Add a11y role "tablist"
Accessibility.setRole(panel.getElement(), Accessibility.ROLE_TABLIST);
panel.setVerticalAlignment(HasVerticalAlignment.ALIGN_BOTTOM);
HTML first = new HTML(" ", true), rest = new HTML(" ", true);
first.setStyleName("gwt-TabBarFirst");
rest.setStyleName("gwt-TabBarRest");
first.setHeight("100%");
rest.setHeight("100%");
panel.add(first);
panel.add(rest);
first.setHeight("100%");
panel.setCellHeight(first, "100%");
panel.setCellWidth(rest, "100%");
setStyleName(first.getElement().getParentElement(),
"gwt-TabBarFirst-wrapper");
setStyleName(rest.getElement().getParentElement(), "gwt-TabBarRest-wrapper");
}
public HandlerRegistration addBeforeSelectionHandler(
BeforeSelectionHandler handler) {
return addHandler(handler, BeforeSelectionEvent.getType());
}
public HandlerRegistration addSelectionHandler(
SelectionHandler handler) {
return addHandler(handler, SelectionEvent.getType());
}
/**
* Adds a new tab with the specified text.
*
* @param html the new tab's html
*/
public void addTab(SafeHtml html) {
addTab(html.asString(), true);
}
/**
* Adds a new tab with the specified text.
*
* @param text the new tab's text
*/
public void addTab(String text) {
insertTab(text, getTabCount());
}
/**
* Adds a new tab with the specified text.
*
* @param text the new tab's text
* @param asHTML true to treat the specified text as html
*/
public void addTab(String text, boolean asHTML) {
insertTab(text, asHTML, getTabCount());
}
/**
* Adds a new tab with the specified widget.
*
* @param widget the new tab's widget
*/
public void addTab(Widget widget) {
insertTab(widget, getTabCount());
}
/**
* @deprecated Use {@link #addBeforeSelectionHandler(BeforeSelectionHandler)}
* and {@link #addSelectionHandler(SelectionHandler)} instead
*/
@Deprecated
public void addTabListener(TabListener listener) {
ListenerWrapper.WrappedTabListener.add(this, listener);
}
/**
* Gets the tab that is currently selected.
*
* @return the selected tab
*/
public int getSelectedTab() {
if (selectedTab == null) {
return -1;
}
return panel.getWidgetIndex(selectedTab) - 1;
}
/**
* Gets the given tab.
*
* This method is final because the Tab interface will expand. Therefore
* it is highly likely that subclasses which implemented this method would end up
* breaking.
*
* @param index the tab's index
* @return the tab wrapper
*/
public final Tab getTab(int index) {
if (index >= getTabCount()) {
return null;
}
ClickDelegatePanel p = (ClickDelegatePanel) panel.getWidget(index + 1);
return p;
}
/**
* Gets the number of tabs present.
*
* @return the tab count
*/
public int getTabCount() {
return panel.getWidgetCount() - 2;
}
/**
* Gets the specified tab's HTML.
*
* @param index the index of the tab whose HTML is to be retrieved
* @return the tab's HTML
*/
public String getTabHTML(int index) {
if (index >= getTabCount()) {
return null;
}
ClickDelegatePanel delPanel = (ClickDelegatePanel) panel.getWidget(index + 1);
SimplePanel focusablePanel = delPanel.getFocusablePanel();
Widget widget = focusablePanel.getWidget();
if (widget instanceof HTML) {
return ((HTML) widget).getHTML();
} else if (widget instanceof Label) {
return ((Label) widget).getText();
} else {
// This will be a focusable panel holding a user-supplied widget.
return focusablePanel.getElement().getParentElement().getInnerHTML();
}
}
/**
* Inserts a new tab at the specified index.
*
* @param html the new tab's html
* @param beforeIndex the index before which this tab will be inserted
*/
public void insertTab(SafeHtml html, int beforeIndex) {
insertTab(html.asString(), true, beforeIndex);
}
/**
* Inserts a new tab at the specified index.
*
* @param text the new tab's text
* @param asHTML true to treat the specified text as HTML
* @param beforeIndex the index before which this tab will be inserted
*/
public void insertTab(String text, boolean asHTML, int beforeIndex) {
checkInsertBeforeTabIndex(beforeIndex);
Label item;
if (asHTML) {
item = new HTML(text);
} else {
item = new Label(text);
}
item.setWordWrap(false);
insertTabWidget(item, beforeIndex);
}
/**
* Inserts a new tab at the specified index.
*
* @param text the new tab's text
* @param beforeIndex the index before which this tab will be inserted
*/
public void insertTab(String text, int beforeIndex) {
insertTab(text, false, beforeIndex);
}
/**
* Inserts a new tab at the specified index.
*
* @param widget widget to be used in the new tab
* @param beforeIndex the index before which this tab will be inserted
*/
public void insertTab(Widget widget, int beforeIndex) {
insertTabWidget(widget, beforeIndex);
}
/**
* Check if a tab is enabled or disabled. If disabled, the user cannot select
* the tab.
*
* @param index the index of the tab
* @return true if the tab is enabled, false if disabled
*/
public boolean isTabEnabled(int index) {
assert (index >= 0) && (index < getTabCount()) : "Tab index out of bounds";
ClickDelegatePanel delPanel = (ClickDelegatePanel) panel.getWidget(index + 1);
return delPanel.isEnabled();
}
/**
* @deprecated add a {@link BeforeSelectionHandler} instead. Alternatively, if
* you need to access to the individual tabs, add a click handler to each
* {@link Tab} element instead.
*/
@Deprecated
public void onClick(Widget sender) {
}
/**
* @deprecated add a key down handler to the individual {@link Tab} objects
* instead.
*/
@Deprecated
public void onKeyDown(Widget sender, char keyCode, int modifiers) {
}
/**
* @deprecated this method has been doing nothing for the entire last release,
* if what you wanted to do was to listen to key press events on tabs, add the
* key press handler to the individual tab wrappers instead.
*/
@Deprecated
public void onKeyPress(Widget sender, char keyCode, int modifiers) {
}
/**
* @deprecated this method has been doing nothing for the entire last release,
* if what you wanted to do was to listen to key up events on tabs, add the
* key up handler to the individual tab wrappers instead.
*
*/
@Deprecated
public void onKeyUp(Widget sender, char keyCode, int modifiers) {
}
/**
* Removes the tab at the specified index.
*
* @param index the index of the tab to be removed
*/
public void removeTab(int index) {
checkTabIndex(index);
// (index + 1) to account for 'first' placeholder widget.
Widget toRemove = panel.getWidget(index + 1);
if (toRemove == selectedTab) {
selectedTab = null;
}
panel.remove(toRemove);
}
/**
* @deprecated Instead use the {@link HandlerRegistration#removeHandler}
* call on the object returned by an add*Handler method
*/
@Deprecated
public void removeTabListener(TabListener listener) {
ListenerWrapper.WrappedTabListener.remove(this, listener);
}
/**
* Programmatically selects the specified tab and fires events. Use index -1
* to specify that no tab should be selected.
*
* @param index the index of the tab to be selected
* @return true if successful, false if the change
* is denied by the {@link BeforeSelectionHandler}.
*/
public boolean selectTab(int index) {
return selectTab(index, true);
}
/**
* Programmatically selects the specified tab. Use index -1 to specify that no
* tab should be selected.
*
* @param index the index of the tab to be selected
* @param fireEvents true to fire events, false not to
* @return true if successful, false if the change
* is denied by the {@link BeforeSelectionHandler}.
*/
public boolean selectTab(int index, boolean fireEvents) {
checkTabIndex(index);
if (fireEvents) {
BeforeSelectionEvent event = BeforeSelectionEvent.fire(this, index);
if (event != null && event.isCanceled()) {
return false;
}
}
// Check for -1.
setSelectionStyle(selectedTab, false);
if (index == -1) {
selectedTab = null;
return true;
}
selectedTab = panel.getWidget(index + 1);
setSelectionStyle(selectedTab, true);
if (fireEvents) {
SelectionEvent.fire(this, index);
}
return true;
}
/**
* Enable or disable a tab. When disabled, users cannot select the tab.
*
* @param index the index of the tab to enable or disable
* @param enabled true to enable, false to disable
*/
public void setTabEnabled(int index, boolean enabled) {
assert (index >= 0) && (index < getTabCount()) : "Tab index out of bounds";
// Style the wrapper
ClickDelegatePanel delPanel = (ClickDelegatePanel) panel.getWidget(index + 1);
delPanel.setEnabled(enabled);
setStyleName(delPanel.getElement(), "gwt-TabBarItem-disabled", !enabled);
setStyleName(delPanel.getElement().getParentElement(),
"gwt-TabBarItem-wrapper-disabled", !enabled);
}
/**
* Sets a tab's contents via HTML.
*
* Use care when setting an object's HTML; it is an easy way to expose
* script-based security problems. Consider using
* {@link #setTabText(int, String)} or {@link #setTabHTML(int, SafeHtml)}
* whenever possible.
*
* @param index the index of the tab whose HTML is to be set
* @param html the tab new HTML
*/
public void setTabHTML(int index, String html) {
assert (index >= 0) && (index < getTabCount()) : "Tab index out of bounds";
ClickDelegatePanel delPanel = (ClickDelegatePanel) panel.getWidget(index + 1);
SimplePanel focusablePanel = delPanel.getFocusablePanel();
focusablePanel.setWidget(new HTML(html, false));
}
/**
* Sets a tab's contents via safe html.
*
* @param index the index of the tab whose HTML is to be set
* @param html the tab new HTML
*/
public void setTabHTML(int index, SafeHtml html) {
setTabHTML(index, html.asString());
}
/**
* Sets a tab's text contents.
*
* @param index the index of the tab whose text is to be set
* @param text the object's new text
*/
public void setTabText(int index, String text) {
assert (index >= 0) && (index < getTabCount()) : "Tab index out of bounds";
ClickDelegatePanel delPanel = (ClickDelegatePanel) panel.getWidget(index + 1);
SimplePanel focusablePanel = delPanel.getFocusablePanel();
// It is not safe to check if the current widget is an instanceof Label and
// reuse it here because HTML is an instanceof Label. Leaving an HTML would
// throw off the results of getTabHTML(int).
focusablePanel.setWidget(new Label(text, false));
}
/**
* Create a {@link SimplePanel} that will wrap the contents in a tab.
* Subclasses can use this method to wrap tabs in decorator panels.
*
* @return a {@link SimplePanel} to wrap the tab contents, or null to leave
* tabs unwrapped
*/
protected SimplePanel createTabTextWrapper() {
return null;
}
/**
* Inserts a new tab at the specified index.
*
* @param widget widget to be used in the new tab
* @param beforeIndex the index before which this tab will be inserted
*/
protected void insertTabWidget(Widget widget, int beforeIndex) {
checkInsertBeforeTabIndex(beforeIndex);
ClickDelegatePanel delWidget = new ClickDelegatePanel(widget);
delWidget.setStyleName(STYLENAME_DEFAULT);
// Add a11y role "tab"
SimplePanel focusablePanel = delWidget.getFocusablePanel();
Accessibility.setRole(focusablePanel.getElement(), Accessibility.ROLE_TAB);
panel.insert(delWidget, beforeIndex + 1);
setStyleName(DOM.getParent(delWidget.getElement()), STYLENAME_DEFAULT
+ "-wrapper", true);
}
/**
* Affected Elements:
*
* - -tab# = The element containing the contents of the tab.
* - -tab-wrapper# = The cell containing the tab at the index.
*
*
* @see UIObject#onEnsureDebugId(String)
*/
@Override
protected void onEnsureDebugId(String baseID) {
super.onEnsureDebugId(baseID);
int numTabs = getTabCount();
for (int i = 0; i < numTabs; i++) {
ClickDelegatePanel delPanel = (ClickDelegatePanel) panel.getWidget(i + 1);
SimplePanel focusablePanel = delPanel.getFocusablePanel();
ensureDebugId(focusablePanel.getContainerElement(), baseID, "tab" + i);
ensureDebugId(DOM.getParent(delPanel.getElement()), baseID, "tab-wrapper"
+ i);
}
}
private void checkInsertBeforeTabIndex(int beforeIndex) {
if ((beforeIndex < 0) || (beforeIndex > getTabCount())) {
throw new IndexOutOfBoundsException();
}
}
private void checkTabIndex(int index) {
if ((index < -1) || (index >= getTabCount())) {
throw new IndexOutOfBoundsException();
}
}
/**
* Selects the tab corresponding to the widget for the tab. To be clear the
* widget for the tab is not the widget INSIDE of the tab; it is the widget
* used to represent the tab itself.
*
* @param tabWidget The widget for the tab to be selected
* @return true if the tab corresponding to the widget for the tab could
* located and selected, false otherwise
*/
private boolean selectTabByTabWidget(Widget tabWidget) {
int numTabs = panel.getWidgetCount() - 1;
for (int i = 1; i < numTabs; ++i) {
if (panel.getWidget(i) == tabWidget) {
return selectTab(i - 1);
}
}
return false;
}
private void setSelectionStyle(Widget item, boolean selected) {
if (item != null) {
if (selected) {
item.addStyleName("gwt-TabBarItem-selected");
setStyleName(DOM.getParent(item.getElement()),
"gwt-TabBarItem-wrapper-selected", true);
} else {
item.removeStyleName("gwt-TabBarItem-selected");
setStyleName(DOM.getParent(item.getElement()),
"gwt-TabBarItem-wrapper-selected", false);
}
}
}
}