Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2017 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.swt.examples.paint; import static org.eclipse.swt.events.SelectionListener.widgetSelectedAdapter; import java.io.InputStream; import java.text.MessageFormat; import java.util.MissingResourceException; import java.util.ResourceBundle; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.accessibility.AccessibleAdapter; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Canvas; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.FontDialog; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Scale; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Text; import org.eclipse.swt.widgets.ToolBar; import org.eclipse.swt.widgets.ToolItem; public class PaintExample { private static ResourceBundle resourceBundle = ResourceBundle.getBundle("examples_paint"); private Composite mainComposite; private Canvas activeForegroundColorCanvas; private Canvas activeBackgroundColorCanvas; private Color paintColorBlack, paintColorWhite; // alias for paintColors[0] and [1] private Color[] paintColors; private Font paintDefaultFont; // do not free private static final int numPaletteRows = 3; private static final int numPaletteCols = 50; private ToolSettings toolSettings; // current active settings private PaintSurface paintSurface; // paint surface for drawing static final int Pencil_tool = 0; static final int Airbrush_tool = 1; static final int Line_tool = 2; static final int PolyLine_tool = 3; static final int Rectangle_tool = 4; static final int RoundedRectangle_tool = 5; static final int Ellipse_tool = 6; static final int Text_tool = 7; static final int None_fill = 8; static final int Outline_fill = 9; static final int Solid_fill = 10; static final int Solid_linestyle = 11; static final int Dash_linestyle = 12; static final int Dot_linestyle = 13; static final int DashDot_linestyle = 14; static final int Font_options = 15; static final int Default_tool = Pencil_tool; static final int Default_fill = None_fill; static final int Default_linestyle = Solid_linestyle; public static final Tool[] tools = { new Tool(Pencil_tool, "Pencil", "tool", SWT.RADIO), new Tool(Airbrush_tool, "Airbrush", "tool", SWT.RADIO), new Tool(Line_tool, "Line", "tool", SWT.RADIO), new Tool(PolyLine_tool, "PolyLine", "tool", SWT.RADIO), new Tool(Rectangle_tool, "Rectangle", "tool", SWT.RADIO), new Tool(RoundedRectangle_tool, "RoundedRectangle", "tool", SWT.RADIO), new Tool(Ellipse_tool, "Ellipse", "tool", SWT.RADIO), new Tool(Text_tool, "Text", "tool", SWT.RADIO), new Tool(None_fill, "None", "fill", SWT.RADIO, Integer.valueOf(ToolSettings.ftNone)), new Tool(Outline_fill, "Outline", "fill", SWT.RADIO, Integer.valueOf(ToolSettings.ftOutline)), new Tool(Solid_fill, "Solid", "fill", SWT.RADIO, Integer.valueOf(ToolSettings.ftSolid)), new Tool(Solid_linestyle, "Solid", "linestyle", SWT.RADIO, Integer.valueOf(SWT.LINE_SOLID)), new Tool(Dash_linestyle, "Dash", "linestyle", SWT.RADIO, Integer.valueOf(SWT.LINE_DASH)), new Tool(Dot_linestyle, "Dot", "linestyle", SWT.RADIO, Integer.valueOf(SWT.LINE_DOT)), new Tool(DashDot_linestyle, "DashDot", "linestyle", SWT.RADIO, Integer.valueOf(SWT.LINE_DASHDOT)), new Tool(Font_options, "Font", "options", SWT.PUSH) }; /** * Creates an instance of a PaintExample embedded inside * the supplied parent Composite. * * @param parent the container of the example */ public PaintExample(Composite parent) { mainComposite = parent; initResources(); initActions(); init(); } /** * Invokes as a standalone program. */ public static void main(String[] args) { Display display = new Display(); Shell shell = new Shell(display); shell.setText(getResourceString("window.title")); shell.setLayout(new GridLayout()); PaintExample instance = new PaintExample(shell); instance.createToolBar(shell); Composite composite = new Composite(shell, SWT.NONE); composite.setLayout(new FillLayout()); composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true)); instance.createGUI(composite); instance.setDefaults(); setShellSize(display, shell); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } instance.dispose(); } /** * Creates the toolbar. * Note: Only called by standalone. */ private void createToolBar(Composite parent) { ToolBar toolbar = new ToolBar(parent, SWT.NONE); String group = null; for (int i = 0; i < tools.length; i++) { Tool tool = tools[i]; if (group != null && !tool.group.equals(group)) { new ToolItem(toolbar, SWT.SEPARATOR); } group = tool.group; ToolItem item = addToolItem(toolbar, tool); if (i == Default_tool || i == Default_fill || i == Default_linestyle) item.setSelection(true); } } /** * Adds a tool item to the toolbar. * Note: Only called by standalone. */ private ToolItem addToolItem(final ToolBar toolbar, final Tool tool) { final String id = tool.group + '.' + tool.name; ToolItem item = new ToolItem(toolbar, tool.type); item.setText(getResourceString(id + ".label")); item.setToolTipText(getResourceString(id + ".tooltip")); item.setImage(tool.image); item.addSelectionListener(widgetSelectedAdapter(e -> tool.action.run())); final int childID = toolbar.indexOf(item); toolbar.getAccessible().addAccessibleListener(new AccessibleAdapter() { @Override public void getName(org.eclipse.swt.accessibility.AccessibleEvent e) { if (e.childID == childID) { e.result = getResourceString(id + ".description"); } } }); return item; } /** * Sets the default tool item states. */ public void setDefaults() { setPaintTool(Default_tool); setFillType(Default_fill); setLineStyle(Default_linestyle); setForegroundColor(paintColorBlack); setBackgroundColor(paintColorWhite); } /** * Creates the GUI. */ public void createGUI(Composite parent) { GridLayout gridLayout; GridData gridData; /*** Create principal GUI layout elements ***/ Composite displayArea = new Composite(parent, SWT.NONE); gridLayout = new GridLayout(); gridLayout.numColumns = 1; displayArea.setLayout(gridLayout); // Creating these elements here avoids the need to instantiate the GUI elements // in strict layout order. The natural layout ordering is an artifact of using // SWT layouts, but unfortunately it is not the same order as that required to // instantiate all of the non-GUI application elements to satisfy referential // dependencies. It is possible to reorder the initialization to some extent, but // this can be very tedious. // paint canvas final Canvas paintCanvas = new Canvas(displayArea, SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL | SWT.NO_REDRAW_RESIZE | SWT.NO_BACKGROUND); gridData = new GridData(GridData.FILL_HORIZONTAL | GridData.FILL_VERTICAL); paintCanvas.setLayoutData(gridData); paintCanvas.setBackground(paintColorWhite); // color selector frame final Composite colorFrame = new Composite(displayArea, SWT.NONE); gridData = new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL); colorFrame.setLayoutData(gridData); // tool settings frame final Composite toolSettingsFrame = new Composite(displayArea, SWT.NONE); gridData = new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL); toolSettingsFrame.setLayoutData(gridData); // status text final Text statusText = new Text(displayArea, SWT.BORDER | SWT.SINGLE | SWT.READ_ONLY); gridData = new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL); statusText.setLayoutData(gridData); /*** Create the remaining application elements inside the principal GUI layout elements ***/ // paintSurface paintSurface = new PaintSurface(paintCanvas, statusText, paintColorWhite); // finish initializing the tool data tools[Pencil_tool].data = new PencilTool(toolSettings, paintSurface); tools[Airbrush_tool].data = new AirbrushTool(toolSettings, paintSurface); tools[Line_tool].data = new LineTool(toolSettings, paintSurface); tools[PolyLine_tool].data = new PolyLineTool(toolSettings, paintSurface); tools[Rectangle_tool].data = new RectangleTool(toolSettings, paintSurface); tools[RoundedRectangle_tool].data = new RoundedRectangleTool(toolSettings, paintSurface); tools[Ellipse_tool].data = new EllipseTool(toolSettings, paintSurface); tools[Text_tool].data = new TextTool(toolSettings, paintSurface); // colorFrame gridLayout = new GridLayout(); gridLayout.numColumns = 3; gridLayout.marginHeight = 0; gridLayout.marginWidth = 0; colorFrame.setLayout(gridLayout); // activeForegroundColorCanvas, activeBackgroundColorCanvas activeForegroundColorCanvas = new Canvas(colorFrame, SWT.BORDER); gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL); gridData.heightHint = 24; gridData.widthHint = 24; activeForegroundColorCanvas.setLayoutData(gridData); activeBackgroundColorCanvas = new Canvas(colorFrame, SWT.BORDER); gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL); gridData.heightHint = 24; gridData.widthHint = 24; activeBackgroundColorCanvas.setLayoutData(gridData); // paletteCanvas final Canvas paletteCanvas = new Canvas(colorFrame, SWT.BORDER | SWT.NO_BACKGROUND); gridData = new GridData(GridData.FILL_HORIZONTAL); gridData.heightHint = 24; paletteCanvas.setLayoutData(gridData); paletteCanvas.addListener(SWT.MouseDown, new Listener() { @Override public void handleEvent(Event e) { Rectangle bounds = paletteCanvas.getClientArea(); Color color = getColorAt(bounds, e.x, e.y); if (e.button == 1) setForegroundColor(color); else setBackgroundColor(color); } private Color getColorAt(Rectangle bounds, int x, int y) { if (bounds.height <= 1 && bounds.width <= 1) return paintColorWhite; final int row = (y - bounds.y) * numPaletteRows / bounds.height; final int col = (x - bounds.x) * numPaletteCols / bounds.width; return paintColors[Math.min(Math.max(row * numPaletteCols + col, 0), paintColors.length - 1)]; } }); Listener refreshListener = e -> { if (e.gc == null) return; Rectangle bounds = paletteCanvas.getClientArea(); for (int row = 0; row < numPaletteRows; ++row) { for (int col = 0; col < numPaletteCols; ++col) { final int x = bounds.width * col / numPaletteCols; final int y = bounds.height * row / numPaletteRows; final int width = Math.max(bounds.width * (col + 1) / numPaletteCols - x, 1); final int height = Math.max(bounds.height * (row + 1) / numPaletteRows - y, 1); e.gc.setBackground(paintColors[row * numPaletteCols + col]); e.gc.fillRectangle(bounds.x + x, bounds.y + y, width, height); } } }; paletteCanvas.addListener(SWT.Resize, refreshListener); paletteCanvas.addListener(SWT.Paint, refreshListener); //paletteCanvas.redraw(); // toolSettingsFrame gridLayout = new GridLayout(); gridLayout.numColumns = 4; gridLayout.marginHeight = 0; gridLayout.marginWidth = 0; toolSettingsFrame.setLayout(gridLayout); Label label = new Label(toolSettingsFrame, SWT.NONE); label.setText(getResourceString("settings.AirbrushRadius.text")); final Scale airbrushRadiusScale = new Scale(toolSettingsFrame, SWT.HORIZONTAL); airbrushRadiusScale.setMinimum(5); airbrushRadiusScale.setMaximum(50); airbrushRadiusScale.setSelection(toolSettings.airbrushRadius); airbrushRadiusScale.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL)); airbrushRadiusScale.addSelectionListener(widgetSelectedAdapter(e -> { toolSettings.airbrushRadius = airbrushRadiusScale.getSelection(); updateToolSettings(); })); label = new Label(toolSettingsFrame, SWT.NONE); label.setText(getResourceString("settings.AirbrushIntensity.text")); final Scale airbrushIntensityScale = new Scale(toolSettingsFrame, SWT.HORIZONTAL); airbrushIntensityScale.setMinimum(1); airbrushIntensityScale.setMaximum(100); airbrushIntensityScale.setSelection(toolSettings.airbrushIntensity); airbrushIntensityScale.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL)); airbrushIntensityScale.addSelectionListener(widgetSelectedAdapter(e -> { toolSettings.airbrushIntensity = airbrushIntensityScale.getSelection(); updateToolSettings(); })); } /** * Disposes of all resources associated with a particular * instance of the PaintExample. */ public void dispose() { if (paintSurface != null) paintSurface.dispose(); if (paintColors != null) { for (final Color color : paintColors) { if (color != null) color.dispose(); } } paintDefaultFont = null; paintColors = null; paintSurface = null; freeResources(); } /** * Frees the resource bundle resources. */ public void freeResources() { for (Tool tool : tools) { final Image image = tool.image; if (image != null) image.dispose(); tool.image = null; } } /** * Returns the Display. * * @return the display we're using */ public Display getDisplay() { return mainComposite.getDisplay(); } /** * Gets a string from the resource bundle. * We don't want to crash because of a missing String. * Returns the key if not found. */ public static String getResourceString(String key) { try { return resourceBundle.getString(key); } catch (MissingResourceException e) { return key; } catch (NullPointerException e) { return "!" + key + "!"; } } /** * Gets a string from the resource bundle and binds it * with the given arguments. If the key is not found, * return the key. */ public static String getResourceString(String key, Object[] args) { try { return MessageFormat.format(getResourceString(key), args); } catch (MissingResourceException e) { return key; } catch (NullPointerException e) { return "!" + key + "!"; } } /** * Initialize colors, fonts, and tool settings. */ private void init() { Display display = mainComposite.getDisplay(); paintColorWhite = new Color(display, 255, 255, 255); paintColorBlack = new Color(display, 0, 0, 0); paintDefaultFont = display.getSystemFont(); paintColors = new Color[numPaletteCols * numPaletteRows]; paintColors[0] = paintColorBlack; paintColors[1] = paintColorWhite; for (int i = 2; i < paintColors.length; i++) { paintColors[i] = new Color(display, ((i * 7) % 255), ((i * 23) % 255), ((i * 51) % 255)); } toolSettings = new ToolSettings(); toolSettings.commonForegroundColor = paintColorBlack; toolSettings.commonBackgroundColor = paintColorWhite; toolSettings.commonFont = paintDefaultFont; } /** * Sets the action field of the tools */ private void initActions() { for (Tool tool2 : tools) { final Tool tool = tool2; String group = tool.group; if (group.equals("tool")) { tool.action = () -> setPaintTool(tool.id); } else if (group.equals("fill")) { tool.action = () -> setFillType(tool.id); } else if (group.equals("linestyle")) { tool.action = () -> setLineStyle(tool.id); } else if (group.equals("options")) { tool.action = () -> { FontDialog fontDialog = new FontDialog(paintSurface.getShell(), SWT.PRIMARY_MODAL); FontData[] fontDatum = toolSettings.commonFont.getFontData(); if (fontDatum != null && fontDatum.length > 0) { fontDialog.setFontList(fontDatum); } fontDialog.setText(getResourceString("options.Font.dialog.title")); paintSurface.hideRubberband(); FontData fontData = fontDialog.open(); paintSurface.showRubberband(); if (fontData != null) { try { Font font = new Font(mainComposite.getDisplay(), fontData); toolSettings.commonFont = font; updateToolSettings(); } catch (SWTException ex) { } } }; } } } /** * Loads the image resources. */ public void initResources() { final Class<PaintExample> clazz = PaintExample.class; if (resourceBundle != null) { try { for (Tool tool2 : tools) { Tool tool = tool2; String id = tool.group + '.' + tool.name; try (InputStream sourceStream = clazz.getResourceAsStream(getResourceString(id + ".image"))) { ImageData source = new ImageData(sourceStream); ImageData mask = source.getTransparencyMask(); tool.image = new Image(null, source, mask); } } return; } catch (Throwable t) { } } String error = (resourceBundle != null) ? getResourceString("error.CouldNotLoadResources") : "Unable to load resources"; freeResources(); throw new RuntimeException(error); } /** * Grabs input focus. */ public void setFocus() { mainComposite.setFocus(); } /** * Sets the tool foreground color. * * @param color the new color to use */ public void setForegroundColor(Color color) { if (activeForegroundColorCanvas != null) activeForegroundColorCanvas.setBackground(color); toolSettings.commonForegroundColor = color; updateToolSettings(); } /** * Set the tool background color. * * @param color the new color to use */ public void setBackgroundColor(Color color) { if (activeBackgroundColorCanvas != null) activeBackgroundColorCanvas.setBackground(color); toolSettings.commonBackgroundColor = color; updateToolSettings(); } /** * Selects a tool given its ID. */ public void setPaintTool(int id) { PaintTool paintTool = (PaintTool) tools[id].data; paintSurface.setPaintSession(paintTool); updateToolSettings(); } /** * Selects a filltype given its ID. */ public void setFillType(int id) { Integer fillType = (Integer) tools[id].data; toolSettings.commonFillType = fillType.intValue(); updateToolSettings(); } /** * Selects line type given its ID. */ public void setLineStyle(int id) { Integer lineType = (Integer) tools[id].data; toolSettings.commonLineStyle = lineType.intValue(); updateToolSettings(); } /** * Sets the size of the shell to it's "packed" size, * unless that makes it bigger than the display, * in which case set it to 9/10 of display size. */ private static void setShellSize(Display display, Shell shell) { Rectangle bounds = display.getBounds(); Point size = shell.computeSize(SWT.DEFAULT, SWT.DEFAULT); if (size.x > bounds.width) size.x = bounds.width * 9 / 10; if (size.y > bounds.height) size.y = bounds.height * 9 / 10; shell.setSize(size); } /** * Notifies the tool that its settings have changed. */ private void updateToolSettings() { final PaintTool activePaintTool = paintSurface.getPaintTool(); if (activePaintTool == null) return; activePaintTool.endSession(); activePaintTool.set(toolSettings); activePaintTool.beginSession(); } }