Java tutorial
package asia.sejong.freedrawing.draw2d.figures; import org.eclipse.jface.resource.ColorRegistry; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.PaintEvent; import org.eclipse.swt.events.PaintListener; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.RGB; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Canvas; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.TypedListener; /** * The SquareButton class is a simple SWT widget that can be used in place of * a native SWT button. Unlike the native button, this should look exactly the * same on all platforms, which is very helpful when designing tightly spaced * multi-platform layouts (I'm looking at you, gigantic blue Mac OS X buttons). * <p> * Here's a simple example: * <p><code> * SquareButton myButton = new SquareButton(composite, SWT.NONE);<br> * myButton.setText("This is my button"); <br> * myButton.addSelectionListener(new SelectionAdapter() { <br> * public void widgetSelected(SelectionEvent event) { <br> * doSomethingAmazing(); // the click action <br> * } <br> * }); <br> * </code><p> * The default button style looks sort of similar to the buttons on the Gmail * web interface. You can very easily create your own styles that look different. * Colors can be specified for when the button is unselected, inactive, focused, * clicked, and hovered over. If two different background colors are specified * for a given button style, the button background will be a top-to-bottom * blended gradient of the two colors. * <p> * You can also specify a background image to be used, either cropped, centered, * stretched, tiled, or set such that the button is exactly the size of the * background image. * <p> * This code may be used under the terms of the Apache license, version 2.0. * Copyright 2009-2010 Strategic Network Applications, Inc. (http://www.snapps.com). * <p> * * @author Julian Robichaux * @version 1.0 * */ public class SquareButton extends Canvas { protected Listener keyListener; protected Image image, backgroundImage; protected String text; protected Font font; protected Color fontColor, hoverFontColor, clickedFontColor, inactiveFontColor, selectedFontColor; protected Color borderColor, hoverBorderColor, clickedBorderColor, inactiveBorderColor, selectedBorderColor; protected Color currentColor, currentColor2, currentFontColor, currentBorderColor; protected Color backgroundColor, backgroundColor2; protected Color clickedColor, clickedColor2; protected Color hoverColor, hoverColor2; protected Color inactiveColor, inactiveColor2; protected Color selectedColor, selectedColor2; protected int innerMarginWidth = 8; protected int innerMarginHeight = 4; protected int borderWidth = 1; protected int imagePadding = 5; protected boolean enabled = true; protected boolean roundedCorners = true; protected boolean isFocused = false; protected boolean selectionBorder = false; private int lastWidth, lastHeight; public static int BG_IMAGE_CROP = 0; public static int BG_IMAGE_STRETCH = 1; public static int BG_IMAGE_TILE = 2; public static int BG_IMAGE_CENTER = 3; public static int BG_IMAGE_FIT = 4; protected int backgroundImageStyle = 0; public static int IMAGE_LEFT = 0; public static int IMAGE_RIGHT = 1; protected int imageStyle = 0; public SquareButton(Composite parent, int style) { super(parent, style | SWT.NO_BACKGROUND); this.setBackgroundMode(SWT.INHERIT_DEFAULT); setDefaultColors(); addListeners(); } protected void widgetDisposed(DisposeEvent e) { // TODO clean up here (listeners?) } protected void addListeners() { addDisposeListener(new DisposeListener() { public void widgetDisposed(DisposeEvent e) { SquareButton.this.widgetDisposed(e); } }); addPaintListener(new PaintListener() { public void paintControl(PaintEvent e) { SquareButton.this.paintControl(e); } }); // MOUSE EVENTS this.addListener(SWT.MouseEnter, new Listener() { public void handleEvent(Event e) { SquareButton.this.setHoverColor(e); } }); this.addListener(SWT.MouseExit, new Listener() { public void handleEvent(Event e) { if (isFocused) SquareButton.this.setSelectedColor(e); else SquareButton.this.setNormalColor(e); } }); this.addListener(SWT.MouseUp, new Listener() { public void handleEvent(Event e) { if (e.button == 1) { SquareButton.this.setHoverColor(e); if ((e.count == 1) && enabled && (getClientArea().contains(e.x, e.y))) { doButtonClicked(); } } } }); this.addListener(SWT.MouseHover, new Listener() { public void handleEvent(Event e) { SquareButton.this.setHoverColor(e); } }); this.addListener(SWT.MouseDown, new Listener() { public void handleEvent(Event e) { if (e.button == 1) { SquareButton.this.setClickedColor(e); } } }); // TAB TRAVERSAL (a KeyDown listener is also required) this.addListener(SWT.Traverse, new Listener() { public void handleEvent(Event e) { switch (e.detail) { case SWT.TRAVERSE_ESCAPE: case SWT.TRAVERSE_RETURN: case SWT.TRAVERSE_TAB_NEXT: case SWT.TRAVERSE_TAB_PREVIOUS: case SWT.TRAVERSE_PAGE_NEXT: case SWT.TRAVERSE_PAGE_PREVIOUS: e.doit = true; break; } } }); this.addListener(SWT.FocusIn, new Listener() { public void handleEvent(Event e) { isFocused = true; SquareButton.this.setSelectedColor(e); redraw(); } }); this.addListener(SWT.FocusOut, new Listener() { public void handleEvent(Event e) { isFocused = false; SquareButton.this.setNormalColor(e); redraw(); } }); this.addListener(SWT.KeyUp, new Listener() { public void handleEvent(Event e) { isFocused = true; SquareButton.this.setSelectedColor(e); redraw(); } }); keyListener = new Listener() { public void handleEvent(Event e) { // required for tab traversal to work switch (e.character) { case ' ': case '\r': case '\n': SquareButton.this.setClickedColor(e); redraw(); doButtonClicked(); break; } } }; setTraversable(true); } /** * SelectionListeners are notified when the button is clicked * * @param listener */ public void addSelectionListener(SelectionListener listener) { addListener(SWT.Selection, new TypedListener(listener)); } public void removeSelectionListener(SelectionListener listener) { removeListener(SWT.Selection, listener); } protected void setTraversable(boolean canTraverse) { // TODO is there a better way to do this? try { if (canTraverse) this.addListener(SWT.KeyDown, keyListener); else if (!canTraverse) this.removeListener(SWT.KeyDown, keyListener); } catch (Exception e) { } } protected void doButtonClicked() { Event e = new Event(); e.item = this; e.widget = this; e.type = SWT.Selection; notifyListeners(SWT.Selection, e); } protected void setDefaultColors() { fontColor = getSavedColor(0, 0, 0); hoverFontColor = getSavedColor(0, 0, 0); clickedFontColor = getSavedColor(255, 255, 255); inactiveFontColor = getSavedColor(187, 187, 187); selectedFontColor = getSavedColor(160, 107, 38); borderColor = getSavedColor(187, 187, 187); hoverBorderColor = getSavedColor(147, 147, 147); clickedBorderColor = getSavedColor(147, 147, 147); inactiveBorderColor = getSavedColor(200, 200, 200); selectedBorderColor = getSavedColor(160, 107, 38); backgroundColor = getSavedColor(248, 248, 248); backgroundColor2 = getSavedColor(228, 228, 228); clickedColor = getSavedColor(120, 120, 120); clickedColor2 = getSavedColor(150, 150, 150); hoverColor = getSavedColor(248, 248, 248); hoverColor2 = getSavedColor(228, 228, 228); inactiveColor = getSavedColor(248, 248, 248); inactiveColor2 = getSavedColor(228, 228, 228); selectedColor = getSavedColor(238, 238, 238); selectedColor2 = getSavedColor(218, 218, 218); } protected Color getSavedColor(int r, int g, int b) { String colorString = "SB_DEFAULT:" + r + "-" + g + "-" + b; ColorRegistry colorRegistry = JFaceResources.getColorRegistry(); if (!colorRegistry.hasValueFor(colorString)) { colorRegistry.put(colorString, new RGB(r, g, b)); } return colorRegistry.get(colorString); } protected void setNormalColor(Event e) { setMouseEventColor(backgroundColor, backgroundColor2, borderColor, fontColor); } protected void setHoverColor(Event e) { setMouseEventColor(hoverColor, hoverColor2, hoverBorderColor, hoverFontColor); } protected void setClickedColor(Event e) { setMouseEventColor(clickedColor, clickedColor2, clickedBorderColor, clickedFontColor); } protected void setInactiveColor(Event e) { setMouseEventColor(inactiveColor, inactiveColor2, inactiveBorderColor, inactiveFontColor); } protected void setSelectedColor(Event e) { setMouseEventColor(selectedColor, selectedColor2, selectedBorderColor, selectedFontColor); } protected void setMouseEventColor(Color bgColor1, Color bgColor2, Color bdrColor, Color fntColor) { if (!this.enabled) return; if (currentColor == null) { currentColor = backgroundColor; currentColor2 = backgroundColor2; currentBorderColor = borderColor; currentFontColor = fontColor; } boolean redrawFlag = false; if ((bgColor1 != null) && (!currentColor.equals(bgColor1))) { currentColor = currentColor2 = bgColor1; if (bgColor2 != null) { currentColor2 = bgColor2; } redrawFlag = true; } if ((bdrColor != null) && (!currentBorderColor.equals(bdrColor))) { currentBorderColor = bdrColor; redrawFlag = true; } if ((fntColor != null) && (!currentFontColor.equals(fntColor))) { currentFontColor = fntColor; redrawFlag = true; } if (redrawFlag) { redraw(); } } private void paintControl(PaintEvent e) { if (currentColor == null) { currentColor = backgroundColor; currentColor2 = backgroundColor2; currentBorderColor = borderColor; currentFontColor = fontColor; } int x = this.innerMarginWidth + 1; int y = this.innerMarginHeight; Point p = this.computeSize(SWT.DEFAULT, SWT.DEFAULT, false); // with certain layouts, the width is sometimes 1 pixel too wide if (p.x > getClientArea().width) { p.x = getClientArea().width; } Rectangle rect = new Rectangle(0, 0, p.x, p.y); GC gc = e.gc; gc.setAntialias(SWT.ON); gc.setAdvanced(true); // add transparency by making the canvas background the same as // the parent background (only needed for rounded corners) if (roundedCorners) { gc.setBackground(getParent().getBackground()); gc.fillRectangle(rect); } // draw the background color of the inside of the button. There's no such // thing as a rounded gradient rectangle in SWT, so we need to draw a filled // rectangle that's just the right size to fit inside a rounded rectangle // without spilling out at the corners gc.setForeground(this.currentColor); gc.setBackground(this.currentColor2); Rectangle fill = new Rectangle(rect.x + 1, rect.y + 1, rect.width - 1, rect.height - 1); if (roundedCorners) { fill = new Rectangle(rect.x + 1, rect.y + 1, rect.width - 2, rect.height - 3); } gc.fillGradientRectangle(fill.x, fill.y, fill.width, fill.height, true); // if there's a background image, draw it on top of the interior color // so any image transparency allows the button colors to come through drawBackgroundImage(gc, fill); // draw the border of the button. If a zero-pixel border was specified, // draw a 1-pixel border the same color as the canvas background instead // so the rounded corners look right gc.setLineStyle(SWT.LINE_SOLID); int arcHeight = Math.max(5, (int) (p.y / 10)); int arcWidth = arcHeight; int bw = borderWidth; if (borderWidth > 0) { gc.setLineWidth(borderWidth); gc.setForeground(this.currentBorderColor); } else { bw = 1; gc.setLineWidth(1); gc.setForeground(getParent().getBackground()); arcWidth = arcHeight += 1; } if (roundedCorners) { gc.drawRoundRectangle(rect.x + (bw - 1), rect.y + (bw - 1), rect.width - bw, rect.height - 2, arcWidth, arcHeight); } else { gc.drawRectangle(rect.x, rect.y, rect.width - bw, rect.height - 1); } // dotted line selection border around the text, if any if (this.isFocused && this.selectionBorder) { gc.setForeground(currentFontColor); gc.setLineStyle(SWT.LINE_DASH); gc.setLineWidth(1); gc.drawRectangle(rect.x + (bw + 1), rect.y + (bw + 1), rect.width - (bw + 5), rect.height - (bw + 5)); } // side image and/or button text, if any if (imageStyle == IMAGE_RIGHT) { drawText(gc, x, y); if (image != null) { x = rect.width - x - image.getBounds().width + imagePadding; drawImage(gc, x, y); } } else { x = drawImage(gc, x, y); drawText(gc, x, y); } } private void drawText(GC gc, int x, int y) { gc.setFont(font); gc.setForeground(currentFontColor); gc.drawText(text, x, y, SWT.DRAW_TRANSPARENT); } private int drawImage(GC gc, int x, int y) { if (image == null) return x; gc.drawImage(image, x, y); return x + image.getBounds().width + imagePadding; } private void drawBackgroundImage(GC gc, Rectangle rect) { if (backgroundImage == null) return; Rectangle imgBounds = backgroundImage.getBounds(); if (backgroundImageStyle == BG_IMAGE_STRETCH) { gc.drawImage(backgroundImage, 0, 0, imgBounds.width, imgBounds.height, rect.x, rect.y, rect.width, rect.height); } else if (backgroundImageStyle == BG_IMAGE_CENTER) { int x = (imgBounds.width - rect.width) / 2; int y = (imgBounds.height - rect.height) / 2; Rectangle centerRect = new Rectangle(rect.x, rect.y, rect.width, rect.height); if (x < 0) { centerRect.x -= x; x = 0; } if (y < 0) { centerRect.y -= y; y = 0; } drawClippedImage(gc, backgroundImage, x, y, centerRect); } else if (backgroundImageStyle == BG_IMAGE_TILE) { for (int y = 0; y < rect.height; y += imgBounds.height) { Rectangle tileRect = new Rectangle(rect.x, y + rect.y, rect.width, rect.height - y); for (int x = 0; x < rect.width; x += imgBounds.width) { tileRect.x += drawClippedImage(gc, backgroundImage, 0, 0, tileRect); tileRect.width -= x; } } } else { // default is BG_IMAGE_CROP drawClippedImage(gc, backgroundImage, 0, 0, rect); } } private int drawClippedImage(GC gc, Image image, int x, int y, Rectangle rect) { if (image != null) { Rectangle imgBounds = image.getBounds(); int width = Math.min(imgBounds.width - x, rect.width); int height = Math.min(imgBounds.height - y, rect.height); gc.drawImage(image, x, y, width, height, rect.x, rect.y, width, height); return width; } return 0; } public Point computeSize(int wHint, int hHint, boolean changed) { if ((wHint == SWT.DEFAULT) && (hHint == SWT.DEFAULT) && !changed && (lastWidth > 0) && (lastHeight > 0)) { return new Point(lastWidth, lastHeight); } int width = 0, height = 0; if (image != null) { Rectangle bounds = image.getBounds(); width = bounds.width + imagePadding; height = bounds.height + (this.innerMarginHeight * 2); } if (text != null) { GC gc = new GC(this); gc.setFont(font); //Point extent = gc.stringExtent(text); // stringExtent ignores linefeeds Point extent = gc.textExtent(text); gc.dispose(); width += extent.x + (this.innerMarginWidth * 2); height = Math.max(height, extent.y + (this.innerMarginHeight * 2)); } if (wHint != SWT.DEFAULT) width = wHint; if (hHint != SWT.DEFAULT) height = hHint; if ((backgroundImage != null) && (backgroundImageStyle == BG_IMAGE_FIT)) { width = backgroundImage.getBounds().width; height = backgroundImage.getBounds().height; } lastWidth = width + 2; lastHeight = height + 2; return new Point(lastWidth, lastHeight); } /** * This is an image that will be displayed to the side of the * text inside the button (if any). By default the image will be * to the left of the text; however, setImageStyle can be used to * specify that it's either to the right or left. If there is no * text, the image will be centered inside the button. * * @param image */ public void setImage(Image image) { this.image = image; redraw(); } public Image getImage() { return image; } /** * Set the style with which the side image is drawn, either IMAGE_LEFT * or IMAGE_RIGHT (default is IMAGE_LEFT). * * @param imageStyle */ public void setImageStyle(int imageStyle) { this.imageStyle = imageStyle; } public int getImageStyle() { return imageStyle; } /** * This is an image that will be used as a background image for the * button, drawn in the manner specified by the backgroundImageStyle * setting. The order in which the button is drawn is: background * color, then background image, then button image and text. So if the * background image has transparency, the background color will show * through the transparency. */ public void setBackgroundImage(Image backgroundImage) { this.backgroundImage = backgroundImage; redraw(); } public Image getBackgroundImage() { return backgroundImage; } /** * Set the style with which the background image is drawn (default is * BG_IMAGE_CROP). The different styles are: * <p><ul> * <li>BG_IMAGE_CROP: the image is drawn once, with the top left corner * of the image at the top left corner of the button. Any part of the image * that is too wide or too tall to fit inside the button area is clipped * (cropped) off.</li> * <li>BG_IMAGE_STRETCH: the image is stretched (or squashed) to exactly * fit the button area.</li> * <li>BG_IMAGE_TILE: the image is tiled vertically and horizontally to * cover the entire button area.</li> * <li>BG_IMAGE_CENTER: the center of the image is placed inside the center * of the button. Any part of the image that is too tall or too wide to fit * will be clipped.</li> * <li>BG_IMAGE_FIT: the button will be the exact size of the image. Note that * this can sometimes truncate the text inside the button.</li> * </ul> * * @param backgroundImageStyle */ public void setBackgroundImageStyle(int backgroundImageStyle) { this.backgroundImageStyle = backgroundImageStyle; } public int getBackgroundImageStyle() { return backgroundImageStyle; } public String getText() { return text; } public void setText(String text) { this.text = text; redraw(); } public Font getFont() { return font; } public void setFont(Font font) { if (font != null) this.font = font; } /** * Set whether or not this button is enabled (active) or * not (inactive). This setting can be changed dynamically * after the button has been drawn. * <p> * An inactive button does not change color * when it is hovered over or clicked, does not receive focus * or participate in the tab order of the widget container, * and does not notify listeners when clicked. */ public void setEnabled(boolean enabled) { boolean oldSetting = this.enabled; this.enabled = enabled; if (oldSetting != enabled) { if (!enabled) { this.enabled = true; this.setInactiveColor(null); this.setTraversable(false); this.enabled = false; } else { this.setNormalColor(null); this.setTraversable(true); } } } public boolean getEnabled() { return enabled; } public boolean isEnabled() { return enabled; } /** * Set the inner margin between the left and right of the text * inside the button and the button borders, in pixels. Like the * left and right padding for the text. Default is 8 pixels. * * @param innerMarginWidth */ public void setInnerMarginWidth(int innerMarginWidth) { if (innerMarginWidth >= 0) this.innerMarginWidth = innerMarginWidth; } public int getInnerMarginWidth() { return innerMarginWidth; } /** * Set the inner margin between the top and bottom of the text * inside the button and the button borders, in pixels. Like the * top and bottom padding for the text. Default is 4 pixels. * * @param innerMarginHeight */ public void setInnerMarginHeight(int innerMarginHeight) { if (innerMarginHeight >= 0) this.innerMarginHeight = innerMarginHeight; } public int getInnerMarginHeight() { return innerMarginHeight; } /** * Set whether or not the button should have rounded corners * (default is true). * * @param roundedCorners */ public void setRoundedCorners(boolean roundedCorners) { this.roundedCorners = roundedCorners; } public boolean hasRoundedCorners() { return roundedCorners; } /** * Set whether or not a dotted-line border should be drawn around * the text inside the button when the button has tab focus. Default is * false (no selection border). If a selection border is used, it will * be the same color as the font color. Note that you can also use * setSelectedColors() to change the look of the button when it has * focus. * * @param selectionBorder */ public void setSelectionBorder(boolean selectionBorder) { this.selectionBorder = selectionBorder; } public boolean hasSelectionBorder() { return selectionBorder; } /** * Set the width of the button border, in pixels (default is 1). * * @param borderWidth */ public void setBorderWidth(int borderWidth) { this.borderWidth = borderWidth; } public int getBorderWidth() { return borderWidth; } /** * The colors of the button in its "default" state (not clicked, selected, etc.) * * @param bgColor1 the gradient color at the top of the button * @param bgColor2 the gradient color at the bottom of the button (if you don't want a gradient, set this to bgColor1) * @param bdrColor the color of the border around the button (if you don't want a border, use getBackground()) * @param fntColor the color of the font inside the button */ public void setDefaultColors(Color bgColor1, Color bgColor2, Color bdrColor, Color fntColor) { if (bgColor1 != null) { this.backgroundColor = bgColor1; } if (bgColor2 != null) { this.backgroundColor2 = bgColor2; } if (bdrColor != null) { this.borderColor = bdrColor; } if (fntColor != null) { this.fontColor = fntColor; } } /** * The colors of the button when the mouse is hovering over it * * @param bgColor1 the gradient color at the top of the button * @param bgColor2 the gradient color at the bottom of the button (if you don't want a gradient, set this to bgColor1) * @param bdrColor the color of the border around the button (if you don't want a border, use getBackground()) * @param fntColor the color of the font inside the button */ public void setHoverColors(Color bgColor1, Color bgColor2, Color bdrColor, Color fntColor) { if (bgColor1 != null) { this.hoverColor = bgColor1; } if (bgColor2 != null) { this.hoverColor2 = bgColor2; } if (bdrColor != null) { this.hoverBorderColor = bdrColor; } if (fntColor != null) { this.hoverFontColor = fntColor; } } /** * The colors of the button when it is being clicked (MouseDown) * * @param bgColor1 the gradient color at the top of the button * @param bgColor2 the gradient color at the bottom of the button (if you don't want a gradient, set this to bgColor1) * @param bdrColor the color of the border around the button (if you don't want a border, use getBackground()) * @param fntColor the color of the font inside the button */ public void setClickedColors(Color bgColor1, Color bgColor2, Color bdrColor, Color fntColor) { if (bgColor1 != null) { this.clickedColor = bgColor1; } if (bgColor2 != null) { this.clickedColor2 = bgColor2; } if (bdrColor != null) { this.clickedBorderColor = bdrColor; } if (fntColor != null) { this.clickedFontColor = fntColor; } } /** * The colors of the button when it has focus * * @param bgColor1 the gradient color at the top of the button * @param bgColor2 the gradient color at the bottom of the button (if you don't want a gradient, set this to bgColor1) * @param bdrColor the color of the border around the button (if you don't want a border, use getBackground()) * @param fntColor the color of the font inside the button */ public void setSelectedColors(Color bgColor1, Color bgColor2, Color bdrColor, Color fntColor) { if (bgColor1 != null) { this.selectedColor = bgColor1; } if (bgColor2 != null) { this.selectedColor2 = bgColor2; } if (bdrColor != null) { this.selectedBorderColor = bdrColor; } if (fntColor != null) { this.selectedFontColor = fntColor; } } /** * The colors of the button when it is in an inactive (not enabled) state * * @param bgColor1 the gradient color at the top of the button * @param bgColor2 the gradient color at the bottom of the button (if you don't want a gradient, set this to bgColor1) * @param bdrColor the color of the border around the button (if you don't want a border, use getBackground()) * @param fntColor the color of the font inside the button */ public void setInactiveColors(Color bgColor1, Color bgColor2, Color bdrColor, Color fntColor) { if (bgColor1 != null) { this.inactiveColor = bgColor1; } if (bgColor2 != null) { this.inactiveColor2 = bgColor2; } if (bdrColor != null) { this.inactiveBorderColor = bdrColor; } if (fntColor != null) { this.inactiveFontColor = fntColor; } } }