/*******************************************************************************
* 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. As a demonstration, cubic and quadratic curves are
* used to spell out "SWT". The user may reposition the cubic and quadratic handles.
*/
public class CurvesSWTTab 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 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 sDiffX1, sDiffY1, sDiffX2, sDiffY2;
/** These are flags that indicate whether or not a handle has been moved. */
private boolean sLeftPtMoved, sRightPtMoved, wPt1Moved, wPt2Moved, tTopPt1Moved, tTopPt2Moved,
tBotPt1Moved, tBotPt2Moved;
/** These rectangles represent the handles on the curves. */
private Rectangle sRect1, sRect2, wRect1, wRect2, tTopRect1, tTopRect2, tBottomRect1, tBottomRect2;
/** These values represent the positions of the curves. */
private float sXPos, sYPos, wXPos, wYPos, topTXPos, topTYPos, botTXPos, botTYPos;
private float tBotDiffX1, tBotDiffY1, tBotDiffX2, tBotDiffY2;
private float tTopDiffX1, tTopDiffY1, tTopDiffX2, tTopDiffY2;
private float wDiffX1, wDiffY1, wDiffX2, wDiffY2;
public CurvesSWTTab(GraphicsExample example) {
super(example);
sRect1 = new Rectangle(-75, 50, 5, 5);
sRect2 = new Rectangle(75, 100, 5, 5);
sDiffX1 = sDiffY1 = 0;
sDiffX2 = sDiffY2 = 0;
wRect1 = new Rectangle(80, 300, 5, 5);
wRect2 = new Rectangle(120, 300, 5, 5);
wDiffX1 = wDiffY1 = wDiffX2 = wDiffY2 = 0;
tTopRect1 = new Rectangle(33, -20, 5, 5);
tTopRect2 = new Rectangle(66, 20, 5, 5);
tTopDiffX1 = tTopDiffY1 = tTopDiffX2 = tTopDiffY2 = 0;
tBottomRect1 = new Rectangle(-33, 50, 5, 5);
tBottomRect2 = new Rectangle(33, 100, 5, 5);
tBotDiffX1 = tBotDiffY1 = tBotDiffX2 = tBotDiffY2 = 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 (sLeftPtMoved) {
sDiffX1 = sDiffX1 + e.x - (int) sXPos - sRect1.x;
sDiffY1 = sDiffY1 + e.y - (int) sYPos - sRect1.y;
sRect1.x = e.x - (int) sXPos;
sRect1.y = e.y - (int) sYPos;
} else if (sRightPtMoved) {
sDiffX2 = sDiffX2 + e.x - (int) sXPos - sRect2.x;
sDiffY2 = sDiffY2 + e.y - (int) sYPos - sRect2.y;
sRect2.x = e.x - (int) sXPos;
sRect2.y = e.y - (int) sYPos;
} else if (wPt1Moved) {
wDiffX1 = wDiffX1 + e.x - (int) wXPos - wRect1.x;
wDiffY1 = wDiffY1 + e.y - (int) wYPos - wRect1.y;
wRect1.x = e.x - (int) wXPos;
wRect1.y = e.y - (int) wYPos;
} else if (wPt2Moved) {
wDiffX2 = wDiffX2 + e.x - (int) wXPos - wRect2.x;
wDiffY2 = wDiffY2 + e.y - (int) wYPos - wRect2.y;
wRect2.x = e.x - (int) wXPos;
wRect2.y = e.y - (int) wYPos;
} else if (tTopPt1Moved) {
tTopDiffX1 = tTopDiffX1 + e.x - (int) topTXPos - tTopRect1.x;
tTopDiffY1 = tTopDiffY1 + e.y - (int) topTYPos - tTopRect1.y;
tTopRect1.x = e.x - (int) topTXPos;
tTopRect1.y = e.y - (int) topTYPos;
} else if (tTopPt2Moved) {
tTopDiffX2 = tTopDiffX2 + e.x - (int) topTXPos - tTopRect2.x;
tTopDiffY2 = tTopDiffY2 + e.y - (int) topTYPos - tTopRect2.y;
tTopRect2.x = e.x - (int) topTXPos;
tTopRect2.y = e.y - (int) topTYPos;
} else if (tBotPt1Moved) {
tBotDiffX1 = tBotDiffX1 + e.x - (int) botTXPos - tBottomRect1.x;
tBotDiffY1 = tBotDiffY1 + e.y - (int) botTYPos - tBottomRect1.y;
tBottomRect1.x = e.x - (int) botTXPos;
tBottomRect1.y = e.y - (int) botTYPos;
} else if (tBotPt2Moved) {
tBotDiffX2 = tBotDiffX2 + e.x - (int) botTXPos - tBottomRect2.x;
tBotDiffY2 = tBotDiffY2 + e.y - (int) botTYPos - tBottomRect2.y;
tBottomRect2.x = e.x - (int) botTXPos;
tBottomRect2.y = e.y - (int) botTYPos;
}
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 r1 = new Rectangle(sRect1.x + (int) sXPos - 1, sRect1.y + (int) sYPos - 1, sRect1.width + 2,
sRect1.height + 2);
Rectangle r2 = new Rectangle(sRect2.x + (int) sXPos - 1, sRect2.y + (int) sYPos - 1, sRect2.width + 2,
sRect2.height + 2);
Rectangle w1 = new Rectangle(wRect1.x + (int) wXPos - 1, wRect1.y + (int) wYPos - 1, wRect1.width + 2,
wRect1.height + 2);
Rectangle w2 = new Rectangle(wRect2.x + (int) wXPos - 1, wRect2.y + (int) wYPos - 1, wRect2.width + 2,
wRect2.height + 2);
Rectangle tTop1 = new Rectangle(tTopRect1.x + (int) topTXPos - 1, tTopRect1.y + (int) topTYPos - 1,
tTopRect1.width + 2, tTopRect1.height + 2);
Rectangle tTop2 = new Rectangle(tTopRect2.x + (int) topTXPos - 1, tTopRect2.y + (int) topTYPos - 1,
tTopRect2.width + 2, tTopRect2.height + 2);
Rectangle tBot1 = new Rectangle(tBottomRect1.x + (int) botTXPos - 1, tBottomRect1.y + (int) botTYPos
- 1, tBottomRect1.width + 2, tBottomRect1.height + 2);
Rectangle tBot2 = new Rectangle(tBottomRect2.x + (int) botTXPos - 1, tBottomRect2.y + (int) botTYPos
- 1, tBottomRect2.width + 2, tBottomRect2.height + 2);
if (r1.contains(e.x, e.y)) {
sLeftPtMoved = true;
mouseDown = true;
} else if (r2.contains(e.x, e.y)) {
sRightPtMoved = true;
mouseDown = true;
} else if (w1.contains(e.x, e.y)) {
wPt1Moved = true;
mouseDown = true;
} else if (w2.contains(e.x, e.y)) {
wPt2Moved = true;
mouseDown = true;
} else if (tTop1.contains(e.x, e.y)) {
tTopPt1Moved = true;
mouseDown = true;
} else if (tTop2.contains(e.x, e.y)) {
tTopPt2Moved = true;
mouseDown = true;
} else if (tBot1.contains(e.x, e.y)) {
tBotPt1Moved = true;
mouseDown = true;
} else if (tBot2.contains(e.x, e.y)) {
tBotPt2Moved = 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 (sLeftPtMoved)
sLeftPtMoved = false;
if (sRightPtMoved)
sRightPtMoved = false;
if (wPt1Moved)
wPt1Moved = false;
if (wPt2Moved)
wPt2Moved = false;
if (tTopPt1Moved)
tTopPt1Moved = false;
if (tTopPt2Moved)
tTopPt2Moved = false;
if (tBotPt1Moved)
tBotPt1Moved = false;
if (tBotPt2Moved)
tBotPt2Moved = 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("CurvesSWTDescription"); //$NON-NLS-1$
}
public boolean getDoubleBuffered() {
return true;
}
public String getText() {
return GraphicsExample.getResourceString("SWT"); //$NON-NLS-1$
}
public void paint(GC gc, int width, int height) {
if (!example.checkAdvancedGraphics())
return;
Device device = gc.getDevice();
Font font = new Font(device, CurvesSWTTab.getPlatformFont(), 16, SWT.ITALIC);
gc.setFont(font);
gc.setLineWidth(2);
Transform transform;
// ----- letter s -----
sXPos = 4 * width / 16;
sYPos = (height - 150) / 2;
transform = new Transform(device);
transform.translate(sXPos, sYPos);
gc.setTransform(transform);
transform.dispose();
gc.setForeground(device.getSystemColor(SWT.COLOR_DARK_BLUE));
gc.drawString(GraphicsExample.getResourceString("Cubic"), 0, 175, true);
Path path = new Path(device);
path.cubicTo(-200 + sDiffX1, 50 + sDiffY1, 200 + sDiffX2, 100 + sDiffY2, 0, 150);
gc.drawPath(path);
path.dispose();
// draw the spline points
gc.setTransform(null);
gc.drawRectangle(sRect1.x + (int) sXPos, sRect1.y + (int) sYPos, sRect1.width, sRect1.height);
gc.drawRectangle(sRect2.x + (int) sXPos, sRect2.y + (int) sYPos, sRect2.width, sRect2.height);
// ----- letter w -----
wXPos = 6 * width / 16;
wYPos = (height - 150) / 2;
transform = new Transform(device);
transform.translate(wXPos, wYPos);
gc.setTransform(transform);
transform.dispose();
gc.setForeground(device.getSystemColor(SWT.COLOR_GRAY));
gc.drawString(GraphicsExample.getResourceString("Quadratic"), 0, -50, true);
gc.drawString(GraphicsExample.getResourceString("Quadratic"), 110, -50, true);
path = new Path(device);
path.quadTo(100 + wDiffX1, 300 + wDiffY1, 100, 0);
path.quadTo(100 + wDiffX2, 300 + wDiffY2, 200, 0);
gc.drawPath(path);
path.dispose();
gc.setTransform(null);
gc.drawRectangle(wRect1.x + (int) wXPos, wRect1.y + (int) wYPos, wRect1.width, wRect1.height);
gc.drawRectangle(wRect2.x + (int) wXPos, wRect2.y + (int) wYPos, wRect2.width, wRect2.height);
// ----- top of letter t -----
topTXPos = 11 * width / 16;
topTYPos = (height - 150) / 2;
transform = new Transform(device);
transform.translate(topTXPos, topTYPos);
gc.setTransform(transform);
transform.dispose();
gc.setForeground(device.getSystemColor(SWT.COLOR_YELLOW));
gc.drawString(GraphicsExample.getResourceString("Cubic"), 25, -50, true);
path = new Path(device);
path.cubicTo(33 + tTopDiffX1, -20 + tTopDiffY1, 66 + tTopDiffX2, 20 + tTopDiffY2, 100, 0);
gc.drawPath(path);
path.dispose();
gc.setTransform(null);
gc.drawRectangle(tTopRect1.x + (int) topTXPos, tTopRect1.y + (int) topTYPos, tTopRect1.width, tTopRect1.height);
gc.drawRectangle(tTopRect2.x + (int) topTXPos, tTopRect2.y + (int) topTYPos, tTopRect2.width, tTopRect2.height);
// ----- vertical bar of letter t -----
botTXPos = 12 * width / 16;
botTYPos = (height - 150) / 2;
transform = new Transform(device);
transform.translate(botTXPos, botTYPos);
gc.setTransform(transform);
transform.dispose();
gc.setForeground(device.getSystemColor(SWT.COLOR_RED));
gc.drawString(GraphicsExample.getResourceString("Cubic"), 0, 175, true);
path = new Path(device);
path.cubicTo(-33 + tBotDiffX1, 50 + tBotDiffY1, 33 + tBotDiffX2, 100 + tBotDiffY2, 0, 150);
gc.drawPath(path);
path.dispose();
gc.setTransform(null);
gc.drawRectangle(tBottomRect1.x + (int) botTXPos, tBottomRect1.y + (int) botTYPos, tBottomRect1.width,
tBottomRect1.height);
gc.drawRectangle(tBottomRect2.x + (int) botTXPos, tBottomRect2.y + (int) botTYPos, tBottomRect2.width,
tBottomRect2.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 r1 = new Rectangle(sRect1.x + (int) sXPos - 1, sRect1.y + (int) sYPos - 1, sRect1.width + 2,
sRect1.height + 2);
Rectangle r2 = new Rectangle(sRect2.x + (int) sXPos - 1, sRect2.y + (int) sYPos - 1, sRect2.width + 2,
sRect2.height + 2);
Rectangle w1 = new Rectangle(wRect1.x + (int) wXPos - 1, wRect1.y + (int) wYPos - 1, wRect1.width + 2,
wRect1.height + 2);
Rectangle w2 = new Rectangle(wRect2.x + (int) wXPos - 1, wRect2.y + (int) wYPos - 1, wRect2.width + 2,
wRect2.height + 2);
Rectangle tTop1 = new Rectangle(tTopRect1.x + (int) topTXPos - 1, tTopRect1.y + (int) topTYPos - 1,
tTopRect1.width + 2, tTopRect1.height + 2);
Rectangle tTop2 = new Rectangle(tTopRect2.x + (int) topTXPos - 1, tTopRect2.y + (int) topTYPos - 1,
tTopRect2.width + 2, tTopRect2.height + 2);
Rectangle tBot1 = new Rectangle(tBottomRect1.x + (int) botTXPos - 1, tBottomRect1.y + (int) botTYPos - 1,
tBottomRect1.width + 2, tBottomRect1.height + 2);
Rectangle tBot2 = new Rectangle(tBottomRect2.x + (int) botTXPos - 1, tBottomRect2.y + (int) botTYPos - 1,
tBottomRect2.width + 2, tBottomRect2.height + 2);
return r1.contains(e.x, e.y) || r2.contains(e.x, e.y) || w1.contains(e.x, e.y) || w2.contains(e.x, e.y)
|| tTop1.contains(e.x, e.y) || tTop2.contains(e.x, e.y) || tBot1.contains(e.x, e.y)
|| tBot2.contains(e.x, e.y);
}
}