/*
* Copyright 2000-2016 JetBrains s.r.o.
*
* 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.intellij.ui;
import com.intellij.openapi.util.Key;
import com.intellij.util.ObjectUtils;
import com.intellij.util.ui.UIUtil;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.TableColumnModel;
import java.awt.*;
import java.awt.event.*;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
public class JBAutoscroller implements ActionListener {
private static final int SCROLL_UPDATE_INTERVAL = 15;
private static final Key<ScrollDeltaProvider> SCROLL_HANDLER_KEY = Key.create("JBAutoScroller.AutoScrollHandler");
private static final JBAutoscroller INSTANCE = new JBAutoscroller();
private final Timer myTimer = UIUtil.createNamedTimer("JBAutoScroller",SCROLL_UPDATE_INTERVAL, this);
private final DefaultScrollDeltaProvider myDefaultAutoScrollHandler = new DefaultScrollDeltaProvider();
private SyntheticDragEvent myLatestDragEvent;
private int myHorizontalScrollDelta;
private int myVerticalScrollDelta;
private JBAutoscroller() {
}
public static void installOn(@NotNull JComponent component, @Nullable AutoscrollLocker locker) {
installOn(component, null, locker);
}
public static void installOn(@NotNull JComponent component, @Nullable ScrollDeltaProvider handler) {
installOn(component, handler, null);
}
public static void installOn(@NotNull JComponent component, @Nullable ScrollDeltaProvider handler, @Nullable AutoscrollLocker locker) {
getInstance().doInstallOn(component, handler, locker);
}
private static JBAutoscroller getInstance() {
return INSTANCE;
}
private void doInstallOn(@NotNull JComponent component, @Nullable ScrollDeltaProvider handler, @Nullable AutoscrollLocker locker) {
component.setAutoscrolls(false); // disable swing autoscroll
if (handler != null) {
component.putClientProperty(SCROLL_HANDLER_KEY, handler);
}
if (component instanceof JTable) {
JTable t = (JTable)component;
new MoveTableCellEditorOnAutoscrollFix(t);
new ScrollOnTableSelectionChangeFix(t, locker);
}
component.addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
start();
}
@Override
public void mouseReleased(MouseEvent e) {
stop();
}
});
component.addMouseMotionListener(new MouseMotionAdapter() {
@Override
public void mouseDragged(MouseEvent e) {
if (e instanceof SyntheticDragEvent) return;
JComponent c = (JComponent)e.getComponent();
ScrollDeltaProvider handler = (ScrollDeltaProvider)c.getClientProperty(SCROLL_HANDLER_KEY);
handler = ObjectUtils.notNull(handler, myDefaultAutoScrollHandler);
myVerticalScrollDelta = handler.getVerticalScrollDelta(e);
myHorizontalScrollDelta = handler.getHorizontalScrollDelta(e);
myLatestDragEvent = new SyntheticDragEvent(c, e.getID(), e.getWhen(), e.getModifiers(),
c.getX(), c.getY(), e.getXOnScreen(), e.getYOnScreen(),
e.getClickCount(), e.isPopupTrigger(), e.getButton());
}
});
}
private void start() {
myVerticalScrollDelta = 0;
myHorizontalScrollDelta = 0;
myTimer.start();
}
private void stop() {
myTimer.stop();
myLatestDragEvent = null;
}
@Override
public void actionPerformed(ActionEvent e) {
if (myLatestDragEvent == null) return;
JComponent component = (JComponent)myLatestDragEvent.getComponent();
if (!component.isShowing()) {
stop();
return;
}
if (autoscroll()) {
fireSyntheticDragEvent(e);
}
}
private void fireSyntheticDragEvent(ActionEvent e) {
Component component = myLatestDragEvent.getComponent();
Point componentOnScreen = component.getLocationOnScreen();
int xScreen = myLatestDragEvent.getXOnScreen();
int yScreen = myLatestDragEvent.getYOnScreen();
int x = xScreen - componentOnScreen.x;
int y = yScreen - componentOnScreen.y;
SyntheticDragEvent dragEvent = new SyntheticDragEvent(component,
myLatestDragEvent.getID(), e.getWhen(),
myLatestDragEvent.getModifiers(),
x, y, xScreen, yScreen,
myLatestDragEvent.getClickCount(),
myLatestDragEvent.isPopupTrigger(),
myLatestDragEvent.getButton());
for (MouseMotionListener l : component.getMouseMotionListeners()) {
l.mouseDragged(dragEvent);
}
}
private boolean autoscroll() {
JScrollPane scrollPane = UIUtil.getParentOfType(JScrollPane.class, myLatestDragEvent.getComponent());
if (scrollPane == null) return false;
boolean scrolled = scroll(scrollPane.getVerticalScrollBar(), myVerticalScrollDelta);
scrolled |= scroll(scrollPane.getHorizontalScrollBar(), myHorizontalScrollDelta);
return scrolled;
}
private boolean isRunningOn(@NotNull JComponent component) {
return myLatestDragEvent != null && myLatestDragEvent.getComponent() == component;
}
private static boolean scroll(@Nullable JScrollBar scrollBar, int delta) {
if (scrollBar == null || delta == 0) return false;
int oldValue = scrollBar.getValue();
scrollBar.setValue(scrollBar.getValue() + delta);
return oldValue != scrollBar.getValue();
}
public interface ScrollDeltaProvider {
int getHorizontalScrollDelta(MouseEvent e);
int getVerticalScrollDelta(MouseEvent e);
}
public static class DefaultScrollDeltaProvider implements ScrollDeltaProvider {
@Override
public int getVerticalScrollDelta(MouseEvent e) {
Rectangle visibleRect = ((JComponent)e.getComponent()).getVisibleRect();
return getScrollDelta(visibleRect.y, visibleRect.y + visibleRect.height - 1, e.getY());
}
@Override
public int getHorizontalScrollDelta(MouseEvent e) {
Rectangle visibleRect = ((JComponent)e.getComponent()).getVisibleRect();
return getScrollDelta(visibleRect.x, visibleRect.x + visibleRect.width - 1, e.getX());
}
protected int getScrollDelta(int low, int high, int value) {
return value - (value > high ? high : value < low ? low : value);
}
}
public static class AutoscrollLocker {
private boolean locked;
public boolean locked() {
return locked;
}
public void runWithLock(Runnable runnable) {
try {
locked = true;
runnable.run();
} finally {
locked = false;
}
}
}
private static class SyntheticDragEvent extends MouseEvent {
public SyntheticDragEvent(Component source, int id, long when, int modifiers,
int x, int y, int xAbs, int yAbs,
int clickCount, boolean popupTrigger, int button) {
super(source, id, when, modifiers, x, y, xAbs, yAbs, clickCount, popupTrigger, button);
}
}
// JTable's UI only updates cell editor location upon it's cell painting which doesn't occur if the cell becomes obscure.
// Moving cell editor prevents it from being 'stuck' on autoscroll.
private static class MoveTableCellEditorOnAutoscrollFix implements AdjustmentListener, PropertyChangeListener {
private final JTable myTable;
public MoveTableCellEditorOnAutoscrollFix(JTable table) {
myTable = table;
JScrollPane scrollPane = UIUtil.getParentOfType(JScrollPane.class, myTable);
assert scrollPane != null : "MoveTableCellEditorOnAutoscrollFix can only be applied to tables having a scrollpane as it's parent!";
scrollPane.addPropertyChangeListener(this);
addScrollBarListener(scrollPane.getHorizontalScrollBar());
addScrollBarListener(scrollPane.getVerticalScrollBar());
}
@Override
public void propertyChange(PropertyChangeEvent evt) {
String propertyName = evt.getPropertyName();
if ("horizontalScrollBar".equals(propertyName) || "verticalScrollBar".equals(propertyName)) {
removeScrollBarListener(ObjectUtils.tryCast(evt.getOldValue(), JScrollBar.class));
addScrollBarListener(ObjectUtils.tryCast(evt.getNewValue(), JScrollBar.class));
}
}
private void addScrollBarListener(@Nullable JScrollBar to) {
if (to != null) {
to.addAdjustmentListener(this);
}
}
private void removeScrollBarListener(@Nullable JScrollBar from) {
if (from != null) {
from.removeAdjustmentListener(this);
}
}
@Override
public void adjustmentValueChanged(AdjustmentEvent e) {
moveCellEditor();
}
private void moveCellEditor() {
int column = myTable.getEditingColumn();
int row = myTable.getEditingRow();
Component editor = myTable.getEditorComponent();
if (column == -1 || row == -1 || editor == null) return;
Rectangle cellRect = myTable.getCellRect(row, column, false);
Rectangle visibleRect = myTable.getVisibleRect();
if (visibleRect.intersects(cellRect)) return;
Rectangle editorBounds = editor.getBounds();
if (!visibleRect.intersects(editorBounds)) return;
editorBounds.x = cellRect.x;
editorBounds.y = cellRect.y;
editor.setBounds(editorBounds);
}
}
// Disabling swing autoscroll on a JTable leads to table not being scrolled on selection changes.
// Particularly, scrollRectToVisible in javax.swing.JTable#changeSelection won't be called.
private static class ScrollOnTableSelectionChangeFix implements ListSelectionListener, PropertyChangeListener {
private final JTable myTable;
private final AutoscrollLocker myLocker;
public ScrollOnTableSelectionChangeFix(JTable table, AutoscrollLocker locker) {
myTable = table;
myLocker = locker;
myTable.addPropertyChangeListener("selectionModel", this);
myTable.addPropertyChangeListener("columnModel", this);
addSelectionListener(getRowSelectionModel());
addSelectionListener(getColumnSelectionModel());
}
@Override
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting() || getInstance().isRunningOn(myTable) || locked()) return;
int row = getLeadSelectionIndexIfSelectionIsNotEmpty(getRowSelectionModel());
int col = getLeadSelectionIndexIfSelectionIsNotEmpty(getColumnSelectionModel());
boolean validRow = (row >= 0 || myTable.getRowCount() == 0) && row < myTable.getRowCount();
boolean validCol = (col >= 0 || myTable.getColumnCount() == 0) && col < myTable.getColumnCount();
if (validRow && validCol) myTable.scrollRectToVisible(myTable.getCellRect(row, col, false));
}
private boolean locked() {
return myLocker != null && myLocker.locked();
}
@Override
public void propertyChange(PropertyChangeEvent evt) {
ListSelectionModel oldSelectionModel = null;
ListSelectionModel newSelectionModel = null;
if ("selectionModel".equals(evt.getPropertyName())) {
oldSelectionModel = (ListSelectionModel)evt.getOldValue();
newSelectionModel = (ListSelectionModel)evt.getNewValue();
}
else if ("columnModel".equals(evt.getPropertyName())) {
TableColumnModel oldColumnModel = (TableColumnModel)evt.getOldValue();
oldSelectionModel = oldColumnModel != null ? oldColumnModel.getSelectionModel() : null;
TableColumnModel newColumnModel = (TableColumnModel)evt.getNewValue();
newSelectionModel = newColumnModel != null ? newColumnModel.getSelectionModel() : null;
}
removeSelectionListener(oldSelectionModel);
addSelectionListener(newSelectionModel);
}
@Nullable
private ListSelectionModel getRowSelectionModel() {
return myTable.getSelectionModel();
}
@Nullable
private ListSelectionModel getColumnSelectionModel() {
return myTable.getColumnModel().getSelectionModel();
}
private void removeSelectionListener(@Nullable ListSelectionModel from) {
if (from != null) {
from.removeListSelectionListener(this);
}
}
private void addSelectionListener(@Nullable ListSelectionModel to) {
if (to != null) {
to.addListSelectionListener(this);
}
}
private static int getLeadSelectionIndexIfSelectionIsNotEmpty(ListSelectionModel lsm) {
return lsm != null && !lsm.isSelectionEmpty() ? lsm.getLeadSelectionIndex() : -1;
}
}
}