| /* |
| * 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.core.client.GWT; |
| import com.google.gwt.event.dom.client.ScrollEvent; |
| import com.google.gwt.event.dom.client.ScrollHandler; |
| import com.google.gwt.event.shared.HandlerRegistration; |
| import com.google.gwt.touch.client.TouchScroller; |
| import com.google.gwt.user.client.DOM; |
| import com.google.gwt.user.client.Element; |
| |
| /** |
| * A simple panel that wraps its contents in a scrollable area. |
| */ |
| @SuppressWarnings("deprecation") |
| public class ScrollPanel extends SimplePanel implements SourcesScrollEvents, |
| RequiresResize, ProvidesResize, HasScrolling { |
| |
| /** |
| * Implementation of this widget. |
| */ |
| static class Impl { |
| /** |
| * Get the maximum horizontal scroll position. |
| * |
| * @param scrollable the scrollable element |
| * @return the maximum scroll position |
| */ |
| public int getMaximumHorizontalScrollPosition(Element scrollable) { |
| return scrollable.getScrollWidth() - scrollable.getClientWidth(); |
| } |
| |
| /** |
| * Get the minimum horizontal scroll position. |
| * |
| * @param scrollable the scrollable element |
| * @return the minimum scroll position |
| */ |
| public int getMinimumHorizontalScrollPosition(Element scrollable) { |
| return 0; |
| } |
| } |
| |
| /** |
| * Firefox scrolls in the negative direction in RTL mode. |
| */ |
| static class ImplRtlReversed extends Impl { |
| @Override |
| public int getMaximumHorizontalScrollPosition(Element scrollable) { |
| return isRtl(scrollable) ? 0 : super |
| .getMaximumHorizontalScrollPosition(scrollable); |
| } |
| |
| @Override |
| public int getMinimumHorizontalScrollPosition(Element scrollable) { |
| return isRtl(scrollable) ? scrollable.getClientWidth() |
| - scrollable.getScrollWidth() : 0; |
| } |
| |
| /** |
| * Check if the specified element has an RTL direction. We can't base this |
| * on the current locale because the user can modify the direction at the |
| * DOM level. |
| * |
| * @param scrollable the scrollable element |
| * @return true if the direction is RTL, false if LTR |
| */ |
| private native boolean isRtl(Element scrollable) /*-{ |
| var computedStyle = $doc.defaultView.getComputedStyle(scrollable, null); |
| return computedStyle.getPropertyValue('direction') == 'rtl'; |
| }-*/; |
| } |
| |
| private static Impl impl; |
| |
| private Element containerElem; |
| |
| /** |
| * The scroller used to support touch events. |
| */ |
| private TouchScroller touchScroller; |
| |
| /** |
| * Creates an empty scroll panel. |
| */ |
| public ScrollPanel() { |
| if (impl == null) { |
| impl = GWT.create(Impl.class); |
| } |
| |
| setAlwaysShowScrollBars(false); |
| |
| containerElem = DOM.createDiv(); |
| getElement().appendChild(containerElem); |
| |
| // Prevent IE standard mode bug when a AbsolutePanel is contained. |
| DOM.setStyleAttribute(getElement(), "position", "relative"); |
| DOM.setStyleAttribute(containerElem, "position", "relative"); |
| |
| // Hack to account for the IE6/7 scrolling bug described here: |
| // http://stackoverflow.com/questions/139000/div-with-overflowauto-and-a-100-wide-table-problem |
| DOM.setStyleAttribute(getElement(), "zoom", "1"); |
| DOM.setStyleAttribute(containerElem, "zoom", "1"); |
| |
| // Enable touch scrolling. |
| setTouchScrollingDisabled(false); |
| } |
| |
| /** |
| * Creates a new scroll panel with the given child widget. |
| * |
| * @param child the widget to be wrapped by the scroll panel |
| */ |
| public ScrollPanel(Widget child) { |
| this(); |
| setWidget(child); |
| } |
| |
| public HandlerRegistration addScrollHandler(ScrollHandler handler) { |
| return addDomHandler(handler, ScrollEvent.getType()); |
| } |
| |
| /** |
| * @deprecated Use {@link #addScrollHandler} instead |
| */ |
| @Deprecated |
| public void addScrollListener(ScrollListener listener) { |
| ListenerWrapper.WrappedScrollListener.add(this, listener); |
| } |
| |
| /** |
| * Ensures that the specified item is visible, by adjusting the panel's scroll |
| * position. |
| * |
| * @param item the item whose visibility is to be ensured |
| */ |
| public void ensureVisible(UIObject item) { |
| Element scroll = getElement(); |
| Element element = item.getElement(); |
| ensureVisibleImpl(scroll, element); |
| } |
| |
| /** |
| * Gets the horizontal scroll position. |
| * |
| * @return the horizontal scroll position, in pixels |
| */ |
| public int getHorizontalScrollPosition() { |
| return DOM.getElementPropertyInt(getElement(), "scrollLeft"); |
| } |
| |
| public int getMaximumHorizontalScrollPosition() { |
| return impl.getMaximumHorizontalScrollPosition(getElement()); |
| } |
| |
| public int getMaximumVerticalScrollPosition() { |
| return getElement().getScrollHeight() - getElement().getClientHeight(); |
| } |
| |
| public int getMinimumHorizontalScrollPosition() { |
| return impl.getMinimumHorizontalScrollPosition(getElement()); |
| } |
| |
| public int getMinimumVerticalScrollPosition() { |
| return 0; |
| } |
| |
| /** |
| * Gets the vertical scroll position. |
| * |
| * @return the vertical scroll position, in pixels |
| * @deprecated as of GWT 2.3, replaced by {@link #getVerticalScrollPosition()} |
| */ |
| @Deprecated |
| public int getScrollPosition() { |
| return DOM.getElementPropertyInt(getElement(), "scrollTop"); |
| } |
| |
| public int getVerticalScrollPosition() { |
| return getScrollPosition(); |
| } |
| |
| /** |
| * Check whether or not touch based scrolling is disabled. This method always |
| * returns false on devices that do not support touch scrolling. |
| * |
| * @return true if disabled, false if enabled |
| */ |
| public boolean isTouchScrollingDisabled() { |
| return touchScroller == null; |
| } |
| |
| public void onResize() { |
| Widget child = getWidget(); |
| if ((child != null) && (child instanceof RequiresResize)) { |
| ((RequiresResize) child).onResize(); |
| } |
| } |
| |
| /** |
| * @deprecated Use the {@link HandlerRegistration#removeHandler} |
| * method on the object returned by {@link #addScrollHandler} instead |
| */ |
| @Deprecated |
| public void removeScrollListener(ScrollListener listener) { |
| ListenerWrapper.WrappedScrollListener.remove(this, listener); |
| } |
| |
| /** |
| * Scroll to the bottom of this panel. |
| */ |
| public void scrollToBottom() { |
| setScrollPosition(DOM.getElementPropertyInt(getElement(), "scrollHeight")); |
| } |
| |
| /** |
| * Scroll to the far left of this panel. |
| */ |
| public void scrollToLeft() { |
| setHorizontalScrollPosition(0); |
| } |
| |
| /** |
| * Scroll to the far right of this panel. |
| */ |
| public void scrollToRight() { |
| setHorizontalScrollPosition(DOM.getElementPropertyInt(getElement(), |
| "scrollWidth")); |
| } |
| |
| /** |
| * Scroll to the top of this panel. |
| */ |
| public void scrollToTop() { |
| setScrollPosition(0); |
| } |
| |
| /** |
| * Sets whether this panel always shows its scroll bars, or only when |
| * necessary. |
| * |
| * @param alwaysShow <code>true</code> to show scroll bars at all times |
| */ |
| public void setAlwaysShowScrollBars(boolean alwaysShow) { |
| DOM.setStyleAttribute(getElement(), "overflow", alwaysShow ? "scroll" |
| : "auto"); |
| } |
| |
| /** |
| * Sets the object's height. This height does not include decorations such as |
| * border, margin, and padding. |
| * |
| * @param height the object's new height, in absolute CSS units (e.g. "10px", |
| * "1em" but not "50%") |
| */ |
| @Override |
| public void setHeight(String height) { |
| super.setHeight(height); |
| } |
| |
| /** |
| * Sets the horizontal scroll position. |
| * |
| * @param position the new horizontal scroll position, in pixels |
| */ |
| public void setHorizontalScrollPosition(int position) { |
| DOM.setElementPropertyInt(getElement(), "scrollLeft", position); |
| } |
| |
| /** |
| * Sets the vertical scroll position. |
| * |
| * @param position the new vertical scroll position, in pixels |
| * @deprecated as of GWT 2.3, replaced by |
| * {@link #setVerticalScrollPosition(int)} |
| */ |
| @Deprecated |
| public void setScrollPosition(int position) { |
| DOM.setElementPropertyInt(getElement(), "scrollTop", position); |
| } |
| |
| /** |
| * Sets the object's size. This size does not include decorations such as |
| * border, margin, and padding. |
| * |
| * @param width the object's new width, in absolute CSS units (e.g. "10px", |
| * "1em", but not "50%") |
| * @param height the object's new height, in absolute CSS units (e.g. "10px", |
| * "1em", but not "50%") |
| */ |
| @Override |
| public void setSize(String width, String height) { |
| super.setSize(width, height); |
| } |
| |
| /** |
| * Set whether or not touch scrolling is disabled. By default, touch scrolling |
| * is enabled on devices that support touch events. |
| * |
| * @param isDisabled true to disable, false to enable |
| * @return true if touch scrolling is enabled and supported, false if disabled |
| * or not supported |
| */ |
| public boolean setTouchScrollingDisabled(boolean isDisabled) { |
| if (isDisabled == isTouchScrollingDisabled()) { |
| return isDisabled; |
| } |
| |
| if (isDisabled) { |
| // Detach the touch scroller. |
| touchScroller.setTargetWidget(null); |
| touchScroller = null; |
| } else { |
| // Attach a new touch scroller. |
| touchScroller = TouchScroller.createIfSupported(this); |
| } |
| return isTouchScrollingDisabled(); |
| } |
| |
| public void setVerticalScrollPosition(int position) { |
| setScrollPosition(position); |
| } |
| |
| /** |
| * Sets the object's width. This width does not include decorations such as |
| * border, margin, and padding. |
| * |
| * @param width the object's new width, in absolute CSS units (e.g. "10px", |
| * "1em", but not "50%") |
| */ |
| @Override |
| public void setWidth(String width) { |
| super.setWidth(width); |
| } |
| |
| @Override |
| protected Element getContainerElement() { |
| return containerElem; |
| } |
| |
| private native void ensureVisibleImpl(Element scroll, Element e) /*-{ |
| if (!e) |
| return; |
| |
| var item = e; |
| var realOffset = 0; |
| while (item && (item != scroll)) { |
| realOffset += item.offsetTop; |
| item = item.offsetParent; |
| } |
| |
| scroll.scrollTop = realOffset - scroll.offsetHeight / 2; |
| }-*/; |
| } |