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This is a backport of OpenJFX 8 to run on Java 7.
The newest version!
/*
* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.javafx.scene.control.skin;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.control.Control;
import javafx.scene.control.IndexedCell;
import javafx.scene.control.ScrollToEvent;
import com.sun.javafx.scene.control.behavior.BehaviorBase;
/**
* Parent class to control skins whose contents are virtualized and scrollable.
* This class handles the interaction with the VirtualFlow class, which is the
* main class handling the virtualization of the contents of this container.
*
* @profile common
*/
public abstract class VirtualContainerBase, I extends IndexedCell> extends BehaviorSkinBase {
protected boolean rowCountDirty;
public VirtualContainerBase(final C control, B behavior) {
super(control, behavior);
flow = new VirtualFlow();
control.addEventHandler(ScrollToEvent.scrollToTopIndex(), new EventHandler>() {
@Override public void handle(ScrollToEvent event) {
// Fix for RT-24630: The row count in VirtualFlow was incorrect
// (normally zero), so the scrollTo call was misbehaving.
if (rowCountDirty) {
// update row count before we do a scroll
updateRowCount();
rowCountDirty = false;
}
flow.scrollTo(event.getScrollTarget());
}
});
}
/**
* The virtualized container which handles the layout and scrolling of
* all the cells.
*/
protected final VirtualFlow flow;
/**
* Returns a Cell available to be used in the virtual flow. This means you
* may return either a previously used, but now unrequired cell, or alternatively
* create a new Cell instance.
*
* Preference is obviously given to reusing cells whenever possible, to keep
* performance costs down.
*/
public abstract I createCell();
/**
* Returns the total number of items in this container, including those
* that are currently hidden because they are out of view.
*/
public abstract int getItemCount();
protected abstract void updateRowCount();
double getMaxCellWidth(int rowsToCount) {
return snappedLeftInset() + flow.getMaxCellWidth(rowsToCount) + snappedRightInset();
}
double getVirtualFlowPreferredHeight(int rows) {
double height = 1.0;
for (int i = 0; i < rows && i < getItemCount(); i++) {
height += flow.getCellLength(i);
}
return height + snappedTopInset() + snappedBottomInset();
}
@Override protected void layoutChildren(double x, double y, double w, double h) {
checkState();
}
protected void checkState() {
if (rowCountDirty) {
updateRowCount();
rowCountDirty = false;
}
}
}