com.google.gwt.user.client.ui.HorizontalSplitPanel 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.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.TextAlign;
import com.google.gwt.i18n.client.LocaleInfo;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Timer;
/**
* A panel that arranges two widgets in a single horizontal row and allows the
* user to interactively change the proportion of the width dedicated to each of
* the two widgets. Widgets contained within a HorizontalSplitPanel
* will be automatically decorated with scrollbars when necessary.
*
*
* This widget will only work in quirks mode. If your application is in
* Standards Mode, use {@link SplitLayoutPanel} instead.
*
*
*
* 
*
*
* CSS Style Rules
*
* - .gwt-HorizontalSplitPanel { the panel itself }
* - .gwt-HorizontalSplitPanel hsplitter { the splitter }
*
*
* @deprecated Use {@link SplitLayoutPanel} instead, but understand that it is
* not a drop in replacement for this class. It requires standards
* mode, and is most easily used under a {@link RootLayoutPanel} (as
* opposed to a {@link RootPanel}
*
* @see SplitLayoutPanel
*/
@Deprecated
public final class HorizontalSplitPanel extends SplitPanel {
/**
* The default resources used by this widget.
*/
public interface Resources extends ClientBundle {
/**
* An image representing the drag thumb.
*/
@Source("splitPanelThumb.png")
ImageResource horizontalSplitPanelThumb();
}
/**
* The standard implementation for horizontal split panels.
*/
private static class Impl {
private static void expandToFitParentHorizontally(Element elem) {
addAbsolutePositoning(elem);
final String zeroSize = "0px";
setTop(elem, zeroSize);
setBottom(elem, zeroSize);
}
protected HorizontalSplitPanel panel;
public void init(HorizontalSplitPanel panel) {
this.panel = panel;
panel.getElement().getStyle().setProperty("position", "relative");
expandToFitParentHorizontally(panel.getElement(LEFT));
expandToFitParentHorizontally(panel.getElement(RIGHT));
expandToFitParentHorizontally(panel.getSplitElement());
expandToFitParentUsingCssOffsets(panel.container);
// Right now, both panes are stacked on top of each other
// on either the left side or the right side of the containing
// panel. This happens because both panes have position:absolute
// and no left/top values. The panes will be on the left side
// if the directionality is LTR, and on the right side if the
// directionality is RTL. In the LTR case, we need to snap the
// right pane to the right of the container, and in the RTL case,
// we need to snap the left pane to the left of the container.
if (LocaleInfo.getCurrentLocale().isRTL()) {
setLeft(panel.getElement(LEFT), "0px");
} else {
setRight(panel.getElement(RIGHT), "0px");
}
}
public void onAttach() {
}
public void onDetach() {
}
public void onSplitResize(int px) {
setSplitPositionUsingPixels(px);
}
public void setSplitPosition(String pos) {
final Element leftElem = panel.getElement(LEFT);
setWidth(leftElem, pos);
setSplitPositionUsingPixels(getOffsetWidth(leftElem));
}
/**
* Set the splitter's position in units of pixels.
*
* px represents the splitter's position as a distance of px pixels from the
* left edge of the container. This is true even in a bidi environment.
* Callers of this method must be aware of this constraint.
*/
public void setSplitPositionUsingPixels(int px) {
final Element splitElem = panel.getSplitElement();
final int rootElemWidth = getOffsetWidth(panel.container);
final int splitElemWidth = getOffsetWidth(splitElem);
// This represents an invalid state where layout is incomplete. This
// typically happens before DOM attachment, but I leave it here as a
// precaution because negative width/height style attributes produce
// errors on IE.
if (rootElemWidth < splitElemWidth) {
return;
}
// Compute the new right side width.
int newRightWidth = rootElemWidth - px - splitElemWidth;
// Constrain the dragging to the physical size of the panel.
if (px < 0) {
px = 0;
newRightWidth = rootElemWidth - splitElemWidth;
} else if (newRightWidth < 0) {
px = rootElemWidth - splitElemWidth;
newRightWidth = 0;
}
final Element rightElem = panel.getElement(RIGHT);
// Set the width of the left side.
setWidth(panel.getElement(LEFT), px + "px");
// Move the splitter to the right edge of the left element.
setLeft(splitElem, px + "px");
// Move the right element to the right of the splitter.
setLeft(rightElem, (px + splitElemWidth) + "px");
updateRightWidth(rightElem, newRightWidth);
}
/**
* Implemented by subclasses.
*
* @param rightElem
* @param newRightWidth
*/
public void updateRightWidth(Element rightElem, int newRightWidth) {
// No need to update the width of the right side; this will be
// recomputed automatically by CSS. This is helpful, as we do not
// have to worry about watching for resize events and adjusting the
// right-side width.
}
}
/**
* The IE8 implementation for horizontal split panels.
*/
@SuppressWarnings("unused")
// will be used by IE8 permutation
private static class ImplIE8 extends Impl {
private boolean isResizeInProgress = false;
private int splitPosition = 0;
@Override
public void init(HorizontalSplitPanel panel) {
this.panel = panel;
final Element elem = panel.getElement();
// Prevents inherited text-align settings from interfering with the
// panel's layout. The setting we choose must be bidi-sensitive,
// as left-alignment is the default with LTR directionality, and
// right-alignment is the default with RTL directionality.
if (LocaleInfo.getCurrentLocale().isRTL()) {
elem.getStyle().setTextAlign(TextAlign.RIGHT);
} else {
elem.getStyle().setTextAlign(TextAlign.LEFT);
}
elem.getStyle().setProperty("position", "relative");
/*
* Technically, these are snapped to the top and bottom, but IE doesn't
* provide a reliable way to make that happen, so a resize listener is
* wired up to control the height of these elements.
*/
addAbsolutePositoning(panel.getElement(LEFT));
addAbsolutePositoning(panel.getElement(RIGHT));
addAbsolutePositoning(panel.getSplitElement());
expandToFitParentUsingPercentages(panel.container);
if (LocaleInfo.getCurrentLocale().isRTL()) {
// Snap the left pane to the left edge of the container. We
// only need to do this when layout is RTL; if we don't, the
// left pane will overlap the right pane.
setLeft(panel.getElement(LEFT), "0px");
}
}
@Override
public void onAttach() {
addResizeListener(panel.container);
onResize();
}
@Override
public void onDetach() {
panel.container.setAttribute("onresize", null);
}
@Override
public void onSplitResize(int px) {
final int resizeUpdatePeriod = 20; // ms
if (!isResizeInProgress) {
isResizeInProgress = true;
new Timer() {
@Override
public void run() {
setSplitPositionUsingPixels(splitPosition);
isResizeInProgress = false;
}
}.schedule(resizeUpdatePeriod);
}
splitPosition = px;
}
@Override
public void setSplitPositionUsingPixels(int px) {
if (LocaleInfo.getCurrentLocale().isRTL()) {
final Element splitElem = panel.getSplitElement();
final int rootElemWidth = getOffsetWidth(panel.container);
final int splitElemWidth = getOffsetWidth(splitElem);
// This represents an invalid state where layout is incomplete. This
// typically happens before DOM attachment, but I leave it here as a
// precaution because negative width/height style attributes produce
// errors on IE.
if (rootElemWidth < splitElemWidth) {
return;
}
// Compute the new right side width.
int newRightWidth = rootElemWidth - px - splitElemWidth;
// Constrain the dragging to the physical size of the panel.
if (px < 0) {
px = 0;
newRightWidth = rootElemWidth - splitElemWidth;
} else if (newRightWidth < 0) {
px = rootElemWidth - splitElemWidth;
newRightWidth = 0;
}
// Set the width of the right side.
setWidth(panel.getElement(RIGHT), newRightWidth + "px");
// Move the splitter to the right edge of the left element.
setLeft(splitElem, px + "px");
// Update the width of the left side
if (px == 0) {
// This takes care of a qurky RTL layout bug with IE6.
// During DOM construction and layout, onResize events
// are fired, and this method is called with px == 0.
// If one tries to set the width of the LEFT element to
// before layout completes, the RIGHT element will
// appear to be blanked out.
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
public void execute() {
setWidth(panel.getElement(LEFT), "0px");
}
});
} else {
setWidth(panel.getElement(LEFT), px + "px");
}
} else {
super.setSplitPositionUsingPixels(px);
}
}
@Override
public void updateRightWidth(Element rightElem, int newRightWidth) {
setWidth(rightElem, newRightWidth + "px");
}
private native void addResizeListener(Element container) /*-{
var self = this;
container.onresize = $entry(function() {
[email protected]$ImplIE8::onResize()();
});
}-*/;
private void onResize() {
final Element leftElem = panel.getElement(LEFT);
final Element rightElem = panel.getElement(RIGHT);
final String height = getOffsetHeight(panel.container) + "px";
setHeight(rightElem, height);
setHeight(panel.getSplitElement(), height);
setHeight(leftElem, height);
setSplitPositionUsingPixels(getOffsetWidth(leftElem));
}
}
/**
* The Safari implementation which owes its existence entirely to a single
* WebKit bug: http://bugs.webkit.org/show_bug.cgi?id=9137.
*/
@SuppressWarnings("unused")
// will be used by Safari permutation
private static class ImplSafari extends Impl {
@Override
public void init(HorizontalSplitPanel panel) {
this.panel = panel;
final String fullSize = "100%";
super.init(panel);
setHeight(panel.container, fullSize);
setHeight(panel.getElement(LEFT), fullSize);
setHeight(panel.getElement(RIGHT), fullSize);
setHeight(panel.getSplitElement(), fullSize);
}
}
/**
* Constant makes for readable calls to {@link #getElement(int)} and
* {@link #getWidget(int)}.
*/
private static final int LEFT = 0;
/**
* Constant makes for readable calls to {@link #getElement(int)} and
* {@link #getWidget(int)}.
*/
private static final int RIGHT = 1;
// A style-free element to serve as the root container.
private final Element container;
private final Impl impl = GWT.create(Impl.class);
/**
* If the split position is set while the split panel is not attached, save it
* here to be applied when the panel is attached to the document.
*/
private String lastSplitPosition = "50%";
private int initialThumbPos;
private int initialLeftWidth;
public HorizontalSplitPanel() {
this(GWT. create(Resources.class));
}
/**
* Creates an empty horizontal split panel.
*
* @param images ImageBundle containing an image for the splitter's drag thumb
* @deprecated replaced by {@link #HorizontalSplitPanel(Resources)}
*/
@Deprecated
public HorizontalSplitPanel(HorizontalSplitPanelImages images) {
this(images.horizontalSplitPanelThumb());
}
/**
* Creates an empty horizontal split panel.
*
* @param resources ClientBundle containing an image for the splitter's drag
* thumb
*/
public HorizontalSplitPanel(Resources resources) {
this(AbstractImagePrototype.create(resources.horizontalSplitPanelThumb()));
}
private HorizontalSplitPanel(AbstractImagePrototype thumbImage) {
super(DOM.createDiv(), DOM.createDiv(), preventBoxStyles(DOM.createDiv()),
preventBoxStyles(DOM.createDiv()));
container = preventBoxStyles(DOM.createDiv());
buildDOM(thumbImage);
setStyleName("gwt-HorizontalSplitPanel");
impl.init(this);
// By default, the panel will fill its parent vertically and horizontally.
// The horizontal case is covered by the fact that the top level div is
// block display.
setHeight("100%");
}
/**
* Adds a widget to a pane in the HorizontalSplitPanel. The method will first
* attempt to add the widget to the left pane. If a widget is already in that
* position, it will attempt to add the widget to the right pane. If a widget
* is already in that position, an exception will be thrown, as a
* HorizontalSplitPanel can contain at most two widgets.
*
* Note that this method is bidi-sensitive. In an RTL environment, this method
* will first attempt to add the widget to the right pane, and if a widget is
* already in that position, it will attempt to add the widget to the left
* pane.
*
* @param w the widget to be added
* @throws IllegalStateException
*/
@Override
public void add(Widget w) {
if (getStartOfLineWidget() == null) {
setStartOfLineWidget(w);
} else if (getEndOfLineWidget() == null) {
setEndOfLineWidget(w);
} else {
throw new IllegalStateException(
"A Splitter can only contain two Widgets.");
}
}
/**
* Gets the widget in the pane that is at the end of the line direction for
* the layout. That is, in an RTL layout, gets the widget in the left pane,
* and in an LTR layout, gets the widget in the right pane.
*
* @return the widget, null if there is not one.
*/
public Widget getEndOfLineWidget() {
return getWidget(getEndOfLinePos());
}
/**
* Gets the widget in the left side of the panel.
*
* @return the widget, null if there is not one.
*/
public Widget getLeftWidget() {
return getWidget(LEFT);
}
/**
* Gets the widget in the right side of the panel.
*
* @return the widget, null if there is not one.
*/
public Widget getRightWidget() {
return getWidget(RIGHT);
}
/**
* Gets the widget in the pane that is at the start of the line direction for
* the layout. That is, in an RTL environment, gets the widget in the right
* pane, and in an LTR environment, gets the widget in the left pane.
*
* @return the widget, null if there is not one.
*/
public Widget getStartOfLineWidget() {
return getWidget(getStartOfLinePos());
}
/**
* Sets the widget in the pane that is at the end of the line direction for
* the layout. That is, in an RTL layout, sets the widget in the left pane,
* and in and RTL layout, sets the widget in the right pane.
*
* @param w the widget
*/
public void setEndOfLineWidget(Widget w) {
setWidget(getEndOfLinePos(), w);
}
/**
* Sets the widget in the left side of the panel.
*
* @param w the widget
*/
public void setLeftWidget(Widget w) {
setWidget(LEFT, w);
}
/**
* Sets the widget in the right side of the panel.
*
* @param w the widget
*/
public void setRightWidget(Widget w) {
setWidget(RIGHT, w);
}
/**
* Moves the position of the splitter.
*
* This method is not bidi-sensitive. The size specified is always the size of
* the left region, regardless of directionality.
*
* @param pos the new size of the left region in CSS units (e.g. "10px",
* "1em")
*/
@Override
public void setSplitPosition(String pos) {
lastSplitPosition = pos;
impl.setSplitPosition(pos);
}
/**
* Sets the widget in the pane that is at the start of the line direction for
* the layout. That is, in an RTL layout, sets the widget in the right pane,
* and in and RTL layout, sets the widget in the left pane.
*
* @param w the widget
*/
public void setStartOfLineWidget(Widget w) {
setWidget(getStartOfLinePos(), w);
}
/**
* Affected Elements:
*
* - -splitter = the container containing the splitter element.
* - -right = the container on the right side of the splitter.
* - -left = the container on the left side of the splitter.
*
*
* @see UIObject#onEnsureDebugId(String)
*/
@Override
protected void onEnsureDebugId(String baseID) {
super.onEnsureDebugId(baseID);
ensureDebugId(getElement(LEFT), baseID, "left");
ensureDebugId(getElement(RIGHT), baseID, "right");
}
@Override
protected void onLoad() {
impl.onAttach();
/*
* If the split position has been changed while detached, apply the change.
* Set the position realizing that it might not work until after layout
* runs. This first call is simply to try to avoid a jitter effect if
* possible.
*/
setSplitPosition(lastSplitPosition);
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
public void execute() {
setSplitPosition(lastSplitPosition);
}
});
}
@Override
protected void onUnload() {
impl.onDetach();
}
@Override
void onSplitterResize(int x, int y) {
impl.onSplitResize(initialLeftWidth + x - initialThumbPos);
}
@Override
void onSplitterResizeStarted(int x, int y) {
initialThumbPos = x;
initialLeftWidth = getOffsetWidth(getElement(LEFT));
}
private void buildDOM(AbstractImagePrototype thumbImage) {
final Element leftDiv = getElement(LEFT);
final Element rightDiv = getElement(RIGHT);
final Element splitDiv = getSplitElement();
DOM.appendChild(getElement(), container);
DOM.appendChild(container, leftDiv);
DOM.appendChild(container, splitDiv);
DOM.appendChild(container, rightDiv);
/*
* Sadly, this is the only way I've found to get vertical centering in this
* case. The usually CSS hacks (display: table-cell, vertical-align: middle)
* don't work in an absolute positioned DIV.
*/
SafeHtmlBuilder sb = new SafeHtmlBuilder();
sb.appendHtmlConstant("");
sb.append(thumbImage.getSafeHtml());
splitDiv.setInnerSafeHtml(sb.toSafeHtml());
addScrolling(leftDiv);
addScrolling(rightDiv);
}
private int getEndOfLinePos() {
return (LocaleInfo.getCurrentLocale().isRTL() ? LEFT : RIGHT);
}
private int getStartOfLinePos() {
return (LocaleInfo.getCurrentLocale().isRTL() ? RIGHT : LEFT);
}
}
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