/*
* Copyright 2000-2007 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.ide.ui.UISettings;
import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.AnActionEvent;
import com.intellij.openapi.actionSystem.CustomShortcutSet;
import com.intellij.openapi.diagnostic.Logger;
import org.jetbrains.annotations.NonNls;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
public class ListScrollingUtil {
private static final Logger LOG = Logger.getInstance("#com.intellij.ui.ListScrollingUtil");
@NonNls
protected static final String SCROLLUP_ACTION_ID = "scrollUp";
@NonNls
protected static final String SCROLLDOWN_ACTION_ID = "scrollDown";
@NonNls
protected static final String SELECT_PREVIOUS_ROW_ACTION_ID = "selectPreviousRow";
@NonNls
protected static final String SELECT_NEXT_ROW_ACTION_ID = "selectNextRow";
@NonNls
protected static final String SELECT_LAST_ROW_ACTION_ID = "selectLastRow";
@NonNls
protected static final String SELECT_FIRST_ROW_ACTION_ID = "selectFirstRow";
public static final int ROW_PADDING = 2;
public static void selectItem(JList list, int index) {
LOG.assertTrue(index >= 0);
LOG.assertTrue(index < list.getModel().getSize());
ensureIndexIsVisible(list, index, 0);
list.setSelectedIndex(index);
}
public static void ensureSelectionExists(JList list) {
int size = list.getModel().getSize();
if (size == 0) {
list.clearSelection();
return;
}
int selectedIndex = list.getSelectedIndex();
if (selectedIndex < 0 || selectedIndex >= size) { // fit index to [0, size-1] range
selectedIndex = 0;
}
selectItem(list, selectedIndex);
}
public static boolean selectItem(JList list, Object item) {
ListModel model = list.getModel();
for (int i = 0; i < model.getSize(); i++) {
Object anItem = model.getElementAt(i);
if (item.equals(anItem)) {
selectItem(list, i);
return true;
}
}
return false;
}
public static void movePageUp(JList list) {
int visible = getVisibleRowCount(list);
if (visible <= 0) {
moveHome(list);
return;
}
int size = list.getModel().getSize();
int decrement = visible - 1;
int index = Math.max(list.getSelectedIndex() - decrement, 0);
int top = list.getFirstVisibleIndex() - decrement;
if (top < 0) {
top = 0;
}
int bottom = top + visible - 1;
if (bottom >= size) {
bottom = size - 1;
}
//list.clearSelection();
Rectangle cellBounds = list.getCellBounds(top, bottom);
if (cellBounds == null) {
moveHome(list);
return;
}
list.scrollRectToVisible(cellBounds);
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
public static void movePageDown(JList list) {
int visible = getVisibleRowCount(list);
if (visible <= 0) {
moveEnd(list);
return;
}
int size = list.getModel().getSize();
int increment = visible - 1;
int index = Math.min(list.getSelectedIndex() + increment, size - 1);
int top = list.getFirstVisibleIndex() + increment;
int bottom = top + visible - 1;
if (bottom >= size) {
bottom = size - 1;
}
//list.clearSelection();
Rectangle cellBounds = list.getCellBounds(top, bottom);
if (cellBounds == null) {
moveEnd(list);
return;
}
list.scrollRectToVisible(cellBounds);
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
public static void moveHome(JList list) {
list.setSelectedIndex(0);
list.ensureIndexIsVisible(0);
}
public static void moveEnd(JList list) {
int index = list.getModel().getSize() - 1;
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
public static void ensureIndexIsVisible(JList list, int index, int moveDirection) {
int visible = getVisibleRowCount(list);
int size = list.getModel().getSize();
int top, bottom;
if (moveDirection == 0) {
top = index - (visible - 1) / ROW_PADDING;
bottom = top + visible - 1;
}
else if (moveDirection < 0) {
top = index - ROW_PADDING;
bottom = index;
}
else {
top = index;
bottom = index + ROW_PADDING;
}
if (top < 0) {
top = 0;
}
if (bottom >= size) {
bottom = size - 1;
}
Rectangle cellBounds = list.getCellBounds(top, bottom);
if (cellBounds != null) {
list.scrollRectToVisible(cellBounds);
}
}
private static int getVisibleRowCount(JList list) {
return list.getLastVisibleIndex() - list.getFirstVisibleIndex() + 1;
}
public static void moveDown(JList list, final int modifiers) {
int size = list.getModel().getSize();
if (size == 0) {
return;
}
final ListSelectionModel selectionModel = list.getSelectionModel();
int index = selectionModel.getLeadSelectionIndex();
boolean cycleScrolling = UISettings.getInstance().CYCLE_SCROLLING;
final int indexToSelect;
if (index < size - 1) {
indexToSelect = index + 1;
}
else if (cycleScrolling && index == size - 1) {
indexToSelect = 0;
}
else {
return;
}
ensureIndexIsVisible(list, indexToSelect, +1);
if (selectionModel.getSelectionMode() == ListSelectionModel.SINGLE_SELECTION) {
list.setSelectedIndex(indexToSelect);
}
else {
if ((modifiers & KeyEvent.SHIFT_DOWN_MASK) == 0) {
selectionModel.removeSelectionInterval(selectionModel.getMinSelectionIndex(), selectionModel.getMaxSelectionIndex());
}
selectionModel.addSelectionInterval(indexToSelect, indexToSelect);
}
}
public static void moveUp(JList list, int modifiers) {
int size = list.getModel().getSize();
int index = list.getSelectedIndex();
boolean cycleScrolling = UISettings.getInstance().CYCLE_SCROLLING;
int indexToSelect;
if (index > 0) {
indexToSelect = index - 1;
}
else if (cycleScrolling && index == 0) {
indexToSelect = size - 1;
}
else {
return;
}
ensureIndexIsVisible(list, indexToSelect, -1);
if (list.getSelectionMode() == ListSelectionModel.SINGLE_SELECTION) {
list.setSelectedIndex(indexToSelect);
}
else {
final ListSelectionModel selectionModel = list.getSelectionModel();
if ((modifiers & KeyEvent.SHIFT_DOWN_MASK) == 0) {
selectionModel.removeSelectionInterval(selectionModel.getMinSelectionIndex(), selectionModel.getMaxSelectionIndex());
}
selectionModel.addSelectionInterval(indexToSelect, indexToSelect);
}
}
public static void installActions(final JList list) {
list.getActionMap().put(SCROLLUP_ACTION_ID, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
movePageUp(list);
}
});
list.getActionMap().put(SCROLLDOWN_ACTION_ID, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
movePageDown(list);
}
});
list.getActionMap().put(SELECT_PREVIOUS_ROW_ACTION_ID, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
moveUp(list, e.getModifiers());
}
});
list.getActionMap().put(SELECT_NEXT_ROW_ACTION_ID, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
moveDown(list, e.getModifiers());
}
});
list.getActionMap().put(SELECT_LAST_ROW_ACTION_ID, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
moveEnd(list);
}
});
list.getActionMap().put(SELECT_FIRST_ROW_ACTION_ID, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
moveHome(list);
}
});
new AnAction() {
public void actionPerformed(AnActionEvent e) {
moveHome(list);
}
}.registerCustomShortcutSet(new CustomShortcutSet(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0)), list);
new AnAction() {
public void actionPerformed(AnActionEvent e) {
moveEnd(list);
}
}.registerCustomShortcutSet(new CustomShortcutSet(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0)), list);
}
}