Java tutorial
//The MIT License // //Copyright (c) 2009 nodchip // //Permission is hereby granted, free of charge, to any person obtaining a copy //of this software and associated documentation files (the "Software"), to deal //in the Software without restriction, including without limitation the rights //to use, copy, modify, merge, publish, distribute, sublicense, and/or sell //copies of the Software, and to permit persons to whom the Software is //furnished to do so, subject to the following conditions: // //The above copyright notice and this permission notice shall be included in //all copies or substantial portions of the Software. // //THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR //IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, //FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE //AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER //LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, //OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN //THE SOFTWARE. package tv.dyndns.kishibe.qmaclone.client.creation; import java.util.ArrayList; import java.util.List; import tv.dyndns.kishibe.qmaclone.client.constant.Constant; import tv.dyndns.kishibe.qmaclone.client.geom.Point; import tv.dyndns.kishibe.qmaclone.client.geom.Polygon; import tv.dyndns.kishibe.qmaclone.client.geom.PolygonException; import tv.dyndns.kishibe.qmaclone.client.geom.Segment; import tv.dyndns.kishibe.qmaclone.client.ui.MouseEventsCanvas; import tv.dyndns.kishibe.qmaclone.client.util.ImageCache; import com.google.gwt.core.client.Scheduler; import com.google.gwt.core.client.Scheduler.ScheduledCommand; import com.google.gwt.dom.client.ImageElement; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.event.dom.client.MouseDownEvent; import com.google.gwt.event.dom.client.MouseDownHandler; import com.google.gwt.event.dom.client.MouseMoveEvent; import com.google.gwt.event.dom.client.MouseMoveHandler; import com.google.gwt.event.dom.client.MouseOutEvent; import com.google.gwt.event.dom.client.MouseOutHandler; import com.google.gwt.event.dom.client.MouseOverEvent; import com.google.gwt.event.dom.client.MouseOverHandler; import com.google.gwt.event.logical.shared.ResizeEvent; import com.google.gwt.event.logical.shared.ResizeHandler; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.DialogBox; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.HorizontalPanel; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.widgetideas.graphics.client.Color; import com.google.gwt.widgetideas.graphics.client.ImageLoader; public class DialogBoxPolygonCreation extends DialogBox implements ClickHandler { private static final String DESCRIPTION = "???????????<br>????????????<br>"; private final Button buttonOk = new Button("OK", this); private final Button buttonCancel = new Button("", this); private final Button buttonUndo = new Button("??", this); private final Button buttonClear = new Button("????", this); private Polygon polygon; // ???? private boolean mouseIn = false; private boolean illegalIfAddPoint = false; private int mouseX = 0; private int mouseY = 0; private static final double LINE_WIDTH = 3.0; private static final Color COLOR_OK = Color.BLUE; private static final Color COLOR_NG = Color.RED; private final List<DialogBoxPolygonCreationListener> listeners = new ArrayList<DialogBoxPolygonCreationListener>(); private final MouseEventsCanvas canvas = new MouseEventsCanvas(Constant.CLICK_IMAGE_WIDTH, Constant.CLICK_IMAGE_HEIGHT); private ImageElement imageElement = null; public DialogBoxPolygonCreation(String imageUrl, String polygonDescription) { super(false, true); setAnimationEnabled(true); setGlassEnabled(true); ImageLoader.loadImages( new String[] { ImageCache.getUrl(imageUrl, Constant.CLICK_IMAGE_WIDTH, Constant.CLICK_IMAGE_HEIGHT) }, callbackLoadImages); canvas.addMouseMoveHandler(imageMouseMoveHandler); canvas.addMouseOutHandler(imageMouseOutHandler); canvas.addMouseOverHandler(imageMouseOverHandler); canvas.addMouseDownHandler(imageMouseDownHandler); try { this.polygon = Polygon.fromString(polygonDescription); } catch (PolygonException e) { this.polygon = new Polygon(); } final VerticalPanel rootPanel = new VerticalPanel(); setWidget(rootPanel); rootPanel.add(canvas); { final HorizontalPanel panel = new HorizontalPanel(); panel.add(buttonOk); panel.add(buttonCancel); panel.add(buttonUndo); panel.add(buttonClear); rootPanel.add(panel); } rootPanel.add(new HTML(DESCRIPTION)); Scheduler.get().scheduleDeferred(new ScheduledCommand() { @Override public void execute() { updateCanvas(); } }); } private final ImageLoader.CallBack callbackLoadImages = new ImageLoader.CallBack() { public void onImagesLoaded(ImageElement[] imageElements) { imageElement = imageElements[0]; } }; private void ok() { hide(); for (DialogBoxPolygonCreationListener listener : listeners) { listener.onOk(); } } private void cancel() { polygon.clear(); hide(); for (DialogBoxPolygonCreationListener listener : listeners) { listener.onCancel(); } } private void undoPolygon() { polygon.remove(polygon.size() - 1); update(); } private void clearPolygon() { polygon.clear(); update(); } private void update() { updateCanvas(); updateWidgets(); } private void updateCanvas() { final boolean ok = mouseIn && illegalIfAddPoint || !mouseIn && checkPolygonCompleted(); final Color color = ok ? COLOR_OK : COLOR_NG; canvas.clear(); if (imageElement != null) { canvas.drawImage(imageElement, 0, 0, Constant.CLICK_IMAGE_WIDTH, Constant.CLICK_IMAGE_HEIGHT); } canvas.setLineWidth(LINE_WIDTH); canvas.setStrokeStyle(color); canvas.beginPath(); final int n = polygon.size(); if (n > 0) { canvas.moveTo(polygon.get(0).x, polygon.get(0).y); for (int i = 1; i < n; ++i) { final Point point = polygon.get(i); canvas.lineTo(point.x, point.y); } if (mouseIn) { canvas.lineTo(mouseX, mouseY); } canvas.lineTo(polygon.get(0).x, polygon.get(0).y); } canvas.stroke(); } private void updateWidgets() { buttonOk.setEnabled(checkPolygonCompleted()); buttonCancel.setEnabled(true); buttonUndo.setEnabled(checkPolygonUndoable()); buttonClear.setEnabled(checkPolygonClearable()); } private void mouseMove(int x, int y) { // System.out.println("mouseMove (" + x + "," + y + ")"); mouseIn = true; mouseX = x; mouseY = y; illegalIfAddPoint = !checkPointCrossingWithMousePointer(); update(); } private void mouseLeave() { // System.out.println("mouseLeave"); mouseIn = false; update(); } private void mouseEnter() { // System.out.println("mouseEnter"); mouseIn = true; update(); } private void mouseDown(int x, int y) { // System.out.println("mouseDown (" + x + ", " + y + ")"); // if (!checkPointAddable()) { // return; // } if (polygon.size() < Constant.MAX_NUMBER_OF_POLYGON_VERTICES) { polygon.add(new Point(x, y)); } update(); } private boolean checkPolygonCompleted() { return polygon.isCompleted(); } private boolean checkPolygonUndoable() { return polygon.size() >= 1; } private boolean checkPolygonClearable() { return polygon.size() >= 1; } private boolean checkPointCrossingWithMousePointer() { final Point currentPoint = new Point(mouseX, mouseY); final int n = polygon.size(); // ????? { for (int i = 0; i < n - 1; ++i) { final Segment segment = new Segment(polygon.get(i), polygon.get(i + 1)); if (segment.on(currentPoint)) { return true; } } } // ??????? if (!polygon.isEmpty()) { final Segment segmentToBegin = new Segment(currentPoint, polygon.get(0)); final Segment segmentToEnd = new Segment(currentPoint, polygon.get(n - 1)); for (int i = 1; i < n - 1; ++i) { final Segment currentSegment = new Segment(polygon.get(i), polygon.get(i + 1)); if (i != 0 && currentSegment.cross(segmentToBegin)) { return true; } } for (int i = 0; i < n - 2; ++i) { final Segment currentSegment = new Segment(polygon.get(i), polygon.get(i + 1)); if (i != n - 2 && currentSegment.cross(segmentToEnd)) { return true; } } } return false; } private final MouseMoveHandler imageMouseMoveHandler = new MouseMoveHandler() { @Override public void onMouseMove(MouseMoveEvent event) { mouseMove(event.getX(), event.getY()); } }; private final MouseOutHandler imageMouseOutHandler = new MouseOutHandler() { @Override public void onMouseOut(MouseOutEvent event) { mouseLeave(); } }; private final MouseOverHandler imageMouseOverHandler = new MouseOverHandler() { @Override public void onMouseOver(MouseOverEvent event) { mouseEnter(); } }; private final MouseDownHandler imageMouseDownHandler = new MouseDownHandler() { @Override public void onMouseDown(MouseDownEvent event) { mouseDown(event.getX(), event.getY()); } }; public String getPolygonDescription() { return polygon.toString(); } public void addDialogBoxPolygonCreationListener(DialogBoxPolygonCreationListener listener) { listeners.add(listener); } public void removeDialogBoxAreaCreationListener(DialogBoxPolygonCreationListener listener) { listeners.remove(listener); } private final ResizeHandler resizeHandler = new ResizeHandler() { @Override public void onResize(ResizeEvent event) { update(); } }; protected void onLoad() { super.onLoad(); Window.addResizeHandler(resizeHandler); } protected void onUnload() { Window.addResizeHandler(resizeHandler); super.onUnload(); } @Override public void onClick(ClickEvent event) { if (event.getSource() == buttonOk) { ok(); } else if (event.getSource() == buttonCancel) { cancel(); } else if (event.getSource() == buttonUndo) { undoPolygon(); } else if (event.getSource() == buttonClear) { clearPolygon(); } } }