// Copyright 2007 Google Inc. All Rights Reserved.
//
// 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.scrollview.events;
import com.google.scrollview.ScrollView;
import com.google.scrollview.ui.SVWindow;
import com.google.scrollview.events.SVEvent;
import com.google.scrollview.events.SVEventType;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.Timer;
import edu.umd.cs.piccolo.PCamera;
import edu.umd.cs.piccolo.PNode;
import edu.umd.cs.piccolo.event.PBasicInputEventHandler;
import edu.umd.cs.piccolo.event.PInputEvent;
import edu.umd.cs.piccolo.nodes.PPath;
/**
* The ScrollViewEventHandler takes care of any events which might happen on the
* canvas and converts them to an according SVEvent, which is (using the
* processEvent method) then added to a message queue. All events from the
* message queue get sent gradually
*
* @author wanke@google.com
*/
public class SVEventHandler extends PBasicInputEventHandler implements
ActionListener, KeyListener, WindowListener {
/** Necessary to wait for a defined period of time (for SVET_HOVER). */
public Timer timer;
/** The window which the event corresponds to. */
private SVWindow svWindow;
/** These are used to determine a selection size (for SVET_SELECTION). */
private int lastX = 0;
private int lastY = 0;
/**
* These are used in case we want to transmit our position, but do not get it
* because it was no MouseEvent, in particular SVET_HOVER and SVET_INPUT.
*/
private int lastXMove = 0;
private int lastYMove = 0;
/** For Drawing a rubber-band rectangle for selection */
private int startX = 0;
private int startY = 0;
private float rubberBandTransparency = 0.5f;
private PNode selection = null;
/** The string entered since the last enter. Since the client
* end eats all newlines, we can't use the newline
* character, so use ! for now, as it cannot be entered
* directly anyway and therefore can never show up for real. */
private String keyStr = "!";
/** Setup the timer. */
public SVEventHandler(SVWindow wdw) {
timer = new Timer(1000, this);
svWindow = wdw;
}
/**
* Store the newest x,y values, add the message to the queue and restart the
* timer.
*/
private void processEvent(SVEvent e) {
lastXMove = e.x;
lastYMove = e.y;
ScrollView.addMessage(e);
timer.restart();
}
/** Show the associated popup menu at (x,y) (relative position of the window). */
private void showPopup(PInputEvent e) {
double x = e.getCanvasPosition().getX();
double y = e.getCanvasPosition().getY();
if (svWindow.svPuMenu != null) {
svWindow.svPuMenu.show(svWindow, (int) x, (int) y);
}
}
/** The mouse is clicked - create an SVET_CLICK event. */
@Override
public void mouseClicked(PInputEvent e) {
if (e.isPopupTrigger()) {
showPopup(e);
} else {
processEvent(new SVEvent(SVEventType.SVET_CLICK, svWindow, (int) e
.getPosition().getX(), (int) e.getPosition().getY(), 0, 0, null));
}
}
/**
* The mouse key is pressed (and keeps getting pressed).
* Depending on the OS, show a popup menu (if the button pressed is associated
* with popup menus, like the RMB under windows&linux) or otherwise save the
* position (in case it is a selection).
*/
@Override
public void mousePressed(PInputEvent e) {
if (e.isPopupTrigger()) {
showPopup(e);
} else {
lastX = (int) e.getPosition().getX();
lastY = (int) e.getPosition().getY();
timer.restart();
}
}
/** The mouse is getting dragged - create an SVET_MOUSE event. */
@Override
public void mouseDragged(PInputEvent e) {
processEvent(new SVEvent(SVEventType.SVET_MOUSE, svWindow, (int) e
.getPosition().getX(), (int) e.getPosition().getY(), (int) e
.getPosition().getX()
- lastX, (int) e.getPosition().getY() - lastY, null));
// Paint a selection rectangle.
if (selection == null) {
startX = (int) e.getPosition().getX();
startY = (int) e.getPosition().getY();
selection = PPath.createRectangle(startX, startY, 1, 1);
selection.setTransparency(rubberBandTransparency);
svWindow.canvas.getLayer().addChild(selection);
} else {
int right = Math.max(startX, (int) e.getPosition().getX());
int left = Math.min(startX, (int) e.getPosition().getX());
int bottom = Math.max(startY, (int) e.getPosition().getY());
int top = Math.min(startY, (int) e.getPosition().getY());
svWindow.canvas.getLayer().removeChild(selection);
selection = PPath.createRectangle(left, top, right - left, bottom - top);
selection.setPaint(Color.YELLOW);
selection.setTransparency(rubberBandTransparency);
svWindow.canvas.getLayer().addChild(selection);
}
}
/**
* The mouse was released.
* Depending on the OS, show a popup menu (if the button pressed is associated
* with popup menus, like the RMB under windows&linux) or otherwise create an
* SVET_SELECTION event.
*/
@Override
public void mouseReleased(PInputEvent e) {
if (e.isPopupTrigger()) {
showPopup(e);
} else {
processEvent(new SVEvent(SVEventType.SVET_SELECTION, svWindow, (int) e
.getPosition().getX(), (int) e.getPosition().getY(), (int) e
.getPosition().getX()
- lastX, (int) e.getPosition().getY() - lastY, null));
}
if (selection != null) {
svWindow.canvas.getLayer().removeChild(selection);
}
}
/**
* The mouse wheel is used to zoom in and out of the viewport and center on
* the (x,y) position the mouse is currently on.
*/
@Override
public void mouseWheelRotated(PInputEvent e) {
PCamera lc = svWindow.canvas.getCamera();
double sf = SVWindow.SCALING_FACTOR;
if (e.getWheelRotation() < 0) {
sf = 1 / sf;
}
lc.scaleViewAboutPoint(lc.getScale() / sf, e.getPosition().getX(), e
.getPosition().getY());
}
/**
* The mouse was moved - create an SVET_MOTION event. NOTE: This obviously
* creates a lot of traffic and, depending on the type of application, could
* quite possibly be disabled.
*/
@Override
public void mouseMoved(PInputEvent e) {
processEvent(new SVEvent(SVEventType.SVET_MOTION, svWindow, (int) e
.getPosition().getX(), (int) e.getPosition().getY(), 0, 0, null));
}
/**
* The mouse entered the window.
* Start the timer, which will then emit SVET_HOVER events every X ms. */
@Override
public void mouseEntered(PInputEvent e) {
timer.restart();
}
/**
* The mouse exited the window
* Stop the timer, so no more SVET_HOVER events will emit. */
@Override
public void mouseExited(PInputEvent e) {
timer.stop();
}
/**
* The only associated object with this is the timer, so we use it to send a
* SVET_HOVER event.
*/
public void actionPerformed(ActionEvent e) {
processEvent(new SVEvent(SVEventType.SVET_HOVER, svWindow, lastXMove,
lastYMove, 0, 0, null));
}
/**
* A key was pressed - create an SVET_INPUT event.
*
* NOTE: Might be useful to specify hotkeys.
*
* Implementation note: The keyListener provided by Piccolo seems to be
* broken, so we use the AWT listener directly.
* There are never any keyTyped events received either so we are
* stuck with physical keys, which is very ugly.
*/
public void keyPressed(KeyEvent e) {
char keyCh = e.getKeyChar();
if (keyCh == '\r' || keyCh == '\n' || keyCh == '\0' || keyCh == '?') {
processEvent(new SVEvent(SVEventType.SVET_INPUT, svWindow, lastXMove,
lastYMove, 0, 0, keyStr));
// Send newline characters as '!' as '!' can never be a keypressed
// and the client eats all newline characters.
keyStr = "!";
} else {
processEvent(new SVEvent(SVEventType.SVET_INPUT, svWindow, lastXMove,
lastYMove, 0, 0, String.valueOf(keyCh)));
keyStr += keyCh;
}
}
/**
* A window is closed (by the 'x') - create an SVET_DESTROY event. If it was
* the last open Window, also send an SVET_EXIT event (but do not exit unless
* the client says so).
*/
public void windowClosing(WindowEvent e) {
processEvent(new SVEvent(SVEventType.SVET_DESTROY, svWindow, lastXMove,
lastYMove, 0, 0, null));
e.getWindow().dispose();
SVWindow.nrWindows--;
if (SVWindow.nrWindows == 0) {
processEvent(new SVEvent(SVEventType.SVET_EXIT, svWindow, lastXMove,
lastYMove, 0, 0, null));
}
}
/** These are all events we do not care about and throw away */
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
}
public void windowActivated(WindowEvent e) {
}
public void windowClosed(WindowEvent e) {
}
public void windowDeactivated(WindowEvent e) {
}
public void windowDeiconified(WindowEvent e) {
}
public void windowIconified(WindowEvent e) {
}
public void windowOpened(WindowEvent e) {
}
}