/*******************************************************************************
* Copyright (c) 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.examples.graphics;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseListener;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Path;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Transform;
import org.eclipse.swt.widgets.Composite;
/**
* This tab presents cubic and quadratic curves that can be drawn. The user may reposition the cubic and quadratic
* handles.
*/
public class CurvesTab extends GraphicsTab {
/**
* Returns the name of a valid font for the resident platform.
*/
static String getPlatformFont() {
if (SWT.getPlatform() == "win32")
return "Arial";
else if (SWT.getPlatform() == "motif")
return "Helvetica";
else if (SWT.getPlatform() == "gtk")
return "Baekmuk Batang";
else if (SWT.getPlatform() == "carbon")
return "Arial";
else
return "Verdana";
}
private float cubDiffX1, cubDiffY1, cubDiffX2, cubDiffY2, cubEndDiffX, cubEndDiffY;
private Cursor cursor;
/** true if hovering over a handle, false otherwise */
private boolean hovering = false;
/** true if left mouse button is held down, false otherwise */
private boolean mouseDown = false;
private MouseListener mouseListener;
private MouseMoveListener mouseMoveListener;
/** These values represent the x and y displacement of each handle. */
private float quadDiffX, quadDiffY, quadEndDiffX, quadEndDiffY;
/** These rectangles represent the handles on the curves. */
private Rectangle quadHndl, quadEndHndl, cubHndl1, cubHndl2, cubEndHndl;
/** These are flags that indicate whether or not a handle has been moved. */
private boolean quadPtMoved, quadEndPtMoved, cubPt1Moved, cubPt2Moved, cubEndPtMoved;
/** These values represent the positions of the curves. */
private float quadXPos, quadYPos, cubXPos, cubYPos;
public CurvesTab(GraphicsExample example) {
super(example);
quadHndl = new Rectangle(200, 150, 5, 5);
quadEndHndl = new Rectangle(400, 0, 5, 5);
quadDiffX = quadDiffY = quadEndDiffX = quadEndDiffY = 0;
cubHndl1 = new Rectangle(133, -60, 5, 5);
cubHndl2 = new Rectangle(266, 60, 5, 5);
cubDiffX1 = cubDiffY1 = cubDiffX2 = cubDiffY2 = 0;
cubEndHndl = new Rectangle(400, 0, 5, 5);
cubEndDiffX = cubEndDiffY = 0;
}
/**
* Creates the widgets used to control the drawing.
*/
public void createControlPanel(Composite parent) {
if (cursor == null)
cursor = new Cursor(parent.getDisplay(), SWT.CURSOR_HAND);
mouseMoveListener = new MouseMoveListener() {
public void mouseMove(MouseEvent e) {
if (hovering && mouseDown)
example.canvas.setCursor(cursor);
else if (isHovering(e)) {
example.canvas.setCursor(cursor);
hovering = true;
} else {
example.canvas.setCursor(null);
hovering = false;
}
if (quadPtMoved) {
quadDiffX = quadDiffX + e.x - (int) quadXPos - quadHndl.x;
quadDiffY = quadDiffY + e.y - (int) quadYPos - quadHndl.y;
quadHndl.x = e.x - (int) quadXPos;
quadHndl.y = e.y - (int) quadYPos;
} else if (quadEndPtMoved) {
quadEndDiffX = quadEndDiffX + e.x - (int) quadXPos - quadEndHndl.x;
quadEndDiffY = quadEndDiffY + e.y - (int) quadYPos - quadEndHndl.y;
quadEndHndl.x = e.x - (int) quadXPos;
quadEndHndl.y = e.y - (int) quadYPos;
} else if (cubPt1Moved) {
cubDiffX1 = cubDiffX1 + e.x - (int) cubXPos - cubHndl1.x;
cubDiffY1 = cubDiffY1 + e.y - (int) cubYPos - cubHndl1.y;
cubHndl1.x = e.x - (int) cubXPos;
cubHndl1.y = e.y - (int) cubYPos;
} else if (cubPt2Moved) {
cubDiffX2 = cubDiffX2 + e.x - (int) cubXPos - cubHndl2.x;
cubDiffY2 = cubDiffY2 + e.y - (int) cubYPos - cubHndl2.y;
cubHndl2.x = e.x - (int) cubXPos;
cubHndl2.y = e.y - (int) cubYPos;
} else if (cubEndPtMoved) {
cubEndDiffX = cubEndDiffX + e.x - (int) cubXPos - cubEndHndl.x;
cubEndDiffY = cubEndDiffY + e.y - (int) cubYPos - cubEndHndl.y;
cubEndHndl.x = e.x - (int) cubXPos;
cubEndHndl.y = e.y - (int) cubYPos;
}
example.redraw();
}
};
mouseListener = new MouseListener() {
public void mouseDoubleClick(MouseEvent e) {
}
/**
* Sent when a mouse button is pressed.
*
* @param e
* an event containing information about the mouse button press
*/
public void mouseDown(MouseEvent e) {
Rectangle quad = new Rectangle(quadHndl.x + (int) quadXPos - 1, quadHndl.y + (int) quadYPos - 1,
quadHndl.width + 2, quadHndl.height + 2);
Rectangle quadEnd = new Rectangle(quadEndHndl.x + (int) quadXPos - 1, quadEndHndl.y + (int) quadYPos
- 1, quadEndHndl.width + 2, quadEndHndl.height + 2);
Rectangle cub1 = new Rectangle(cubHndl1.x + (int) cubXPos - 1, cubHndl1.y + (int) cubYPos - 1,
cubHndl1.width + 2, cubHndl1.height + 2);
Rectangle cub2 = new Rectangle(cubHndl2.x + (int) cubXPos - 1, cubHndl2.y + (int) cubYPos - 1,
cubHndl2.width + 2, cubHndl2.height + 2);
Rectangle cubEnd = new Rectangle(cubEndHndl.x + (int) cubXPos - 1, cubEndHndl.y + (int) cubYPos - 1,
cubEndHndl.width + 2, cubEndHndl.height + 2);
if (quad.contains(e.x, e.y)) {
quadPtMoved = true;
mouseDown = true;
} else if (quadEnd.contains(e.x, e.y)) {
quadEndPtMoved = true;
mouseDown = true;
} else if (cub1.contains(e.x, e.y)) {
cubPt1Moved = true;
mouseDown = true;
} else if (cub2.contains(e.x, e.y)) {
cubPt2Moved = true;
mouseDown = true;
} else if (cubEnd.contains(e.x, e.y)) {
cubEndPtMoved = true;
mouseDown = true;
}
}
/**
* Sent when a mouse button is released.
*
* @param e
* an event containing information about the mouse button release
*/
public void mouseUp(MouseEvent e) {
mouseDown = false;
if (isHovering(e))
example.canvas.setCursor(cursor);
else
example.canvas.setCursor(null);
if (quadPtMoved)
quadPtMoved = false;
if (quadEndPtMoved)
quadEndPtMoved = false;
if (cubPt1Moved)
cubPt1Moved = false;
if (cubPt2Moved)
cubPt2Moved = false;
if (cubEndPtMoved)
cubEndPtMoved = false;
example.redraw();
}
};
example.canvas.addMouseMoveListener(mouseMoveListener);
example.canvas.addMouseListener(mouseListener);
}
public void dispose() {
if (mouseListener != null)
example.canvas.removeMouseListener(mouseListener);
if (mouseMoveListener != null)
example.canvas.removeMouseMoveListener(mouseMoveListener);
if (cursor != null) {
cursor.dispose();
cursor = null;
}
}
public String getCategory() {
return GraphicsExample.getResourceString("Curves"); //$NON-NLS-1$
}
public String getDescription() {
return GraphicsExample.getResourceString("CurvesDescription"); //$NON-NLS-1$
}
public boolean getDoubleBuffered() {
return true;
}
public String getText() {
return GraphicsExample.getResourceString("Curves"); //$NON-NLS-1$
}
public void paint(GC gc, int width, int height) {
if (!example.checkAdvancedGraphics())
return;
Device device = gc.getDevice();
Font font = new Font(device, CurvesTab.getPlatformFont(), 16, SWT.ITALIC);
gc.setFont(font);
gc.setLineWidth(5);
Transform transform;
// ----- cubic curve -----
cubXPos = width / 5;
cubYPos = height / 3;
transform = new Transform(device);
transform.translate(cubXPos, cubYPos);
gc.setTransform(transform);
transform.dispose();
gc.setForeground(device.getSystemColor(SWT.COLOR_RED));
gc.drawString(GraphicsExample.getResourceString("Cubic"), 25, -70, true);
Path path = new Path(device);
path.cubicTo(133 + cubDiffX1, -60 + cubDiffY1, 266 + cubDiffX2, 60 + cubDiffY2, 400 + cubEndDiffX,
0 + cubEndDiffY);
gc.drawPath(path);
path.dispose();
gc.setTransform(null);
gc.setForeground(device.getSystemColor(SWT.COLOR_DARK_BLUE));
gc.drawRectangle(cubHndl1.x + (int) cubXPos, cubHndl1.y + (int) cubYPos, cubHndl1.width, cubHndl1.height);
gc.drawRectangle(cubHndl2.x + (int) cubXPos, cubHndl2.y + (int) cubYPos, cubHndl2.width, cubHndl2.height);
gc.drawRectangle(cubEndHndl.x + (int) cubXPos, cubEndHndl.y + (int) cubYPos, cubEndHndl.width,
cubEndHndl.height);
// ----- quadratic curve -----
quadXPos = width / 5;
quadYPos = 2 * height / 3;
transform = new Transform(device);
transform.translate(quadXPos, quadYPos);
gc.setTransform(transform);
transform.dispose();
gc.setForeground(device.getSystemColor(SWT.COLOR_GREEN));
gc.drawString(GraphicsExample.getResourceString("Quadratic"), 0, -50, true);
path = new Path(device);
path.quadTo(200 + quadDiffX, 150 + quadDiffY, 400 + quadEndDiffX, 0 + quadEndDiffY);
gc.drawPath(path);
path.dispose();
gc.setTransform(null);
gc.setForeground(device.getSystemColor(SWT.COLOR_GRAY));
gc.drawRectangle(quadHndl.x + (int) quadXPos, quadHndl.y + (int) quadYPos, quadHndl.width, quadHndl.height);
gc.drawRectangle(quadEndHndl.x + (int) quadXPos, quadEndHndl.y + (int) quadYPos, quadEndHndl.width,
quadEndHndl.height);
font.dispose();
}
/**
* This helper method determines whether or not the cursor is positioned over a handle.
*
* @param e
* A MouseEvent
* @return true if cursor is positioned over a handle; false otherwise
*/
private boolean isHovering(MouseEvent e) {
Rectangle quad = new Rectangle(quadHndl.x + (int) quadXPos - 1, quadHndl.y + (int) quadYPos - 1,
quadHndl.width + 2, quadHndl.height + 2);
Rectangle quadEnd = new Rectangle(quadEndHndl.x + (int) quadXPos - 1, quadEndHndl.y + (int) quadYPos - 1,
quadEndHndl.width + 2, quadEndHndl.height + 2);
Rectangle cub1 = new Rectangle(cubHndl1.x + (int) cubXPos - 1, cubHndl1.y + (int) cubYPos - 1,
cubHndl1.width + 2, cubHndl1.height + 2);
Rectangle cub2 = new Rectangle(cubHndl2.x + (int) cubXPos - 1, cubHndl2.y + (int) cubYPos - 1,
cubHndl2.width + 2, cubHndl2.height + 2);
Rectangle cubEnd = new Rectangle(cubEndHndl.x + (int) cubXPos - 1, cubEndHndl.y + (int) cubYPos - 1,
cubEndHndl.width + 2, cubEndHndl.height + 2);
return quad.contains(e.x, e.y) || quadEnd.contains(e.x, e.y) || cub1.contains(e.x, e.y)
|| cub2.contains(e.x, e.y) || cubEnd.contains(e.x, e.y);
}
}