imageanalyzer.java

SWT开发例子

			loader = new ImageLoader();
			if (incremental) {
				// Prepare to handle incremental events.
				loader.addImageLoaderListener(new ImageLoaderListener() {
					public void imageDataLoaded(ImageLoaderEvent event) {
						incrementalDataLoaded(event);
					}
				});
				incrementalThreadStart();
			}
			// Read the new image(s) from the chosen file.
			long startTime = System.currentTimeMillis();
			imageDataArray = loader.load(filename);
			loadTime = System.currentTimeMillis() - startTime;
			if (imageDataArray.length > 0) {
				// Cache the filename.
				currentName = filename;
				fileName = filename;
				
				// If there are multiple images in the file (typically GIF)
				// then enable the Previous, Next and Animate buttons.
				previousButton.setEnabled(imageDataArray.length > 1);
				nextButton.setEnabled(imageDataArray.length > 1);
				animateButton.setEnabled(imageDataArray.length > 1 && loader.logicalScreenWidth > 0 && loader.logicalScreenHeight > 0);
	
				// Display the first image in the file.
				imageDataIndex = 0;
				displayImage(imageDataArray[imageDataIndex]);
				resetScrollBars();
			}
		} catch (SWTException e) {
			showErrorDialog(bundle.getString("Loading_lc"), filename, e);
		} catch (SWTError e) {
			showErrorDialog(bundle.getString("Loading_lc"), filename, e);
		} finally {
			shell.setCursor(null);
			imageCanvas.setCursor(crossCursor);
			waitCursor.dispose();
		}
	}
	
	void menuOpenURL() {
		animate = false; // stop any animation in progress
		resetScaleCombos();
		
		// Get the user to choose an image URL.
		TextPrompter textPrompter = new TextPrompter(shell, SWT.APPLICATION_MODAL | SWT.DIALOG_TRIM);
		textPrompter.setText(bundle.getString("OpenURLDialog"));
		textPrompter.setMessage(bundle.getString("EnterURL"));
		String urlname = textPrompter.open();
		if (urlname == null) return;

		Cursor waitCursor = new Cursor(display, SWT.CURSOR_WAIT);
		shell.setCursor(waitCursor);
		imageCanvas.setCursor(waitCursor);
		try {
			URL url = new URL(urlname);
			InputStream stream = url.openStream();
			loader = new ImageLoader();
			if (incremental) {
				// Prepare to handle incremental events.
				loader.addImageLoaderListener(new ImageLoaderListener() {
					public void imageDataLoaded(ImageLoaderEvent event) {
						incrementalDataLoaded(event);
					}
				});
				incrementalThreadStart();
			}
			// Read the new image(s) from the chosen file.
			long startTime = System.currentTimeMillis();
			imageDataArray = loader.load(stream);
			loadTime = System.currentTimeMillis() - startTime;
			if (imageDataArray.length > 0) {
				currentName = urlname;
				fileName = null;
				
				// If there are multiple images in the file (typically GIF)
				// then enable the Previous, Next and Animate buttons.
				previousButton.setEnabled(imageDataArray.length > 1);
				nextButton.setEnabled(imageDataArray.length > 1);
				animateButton.setEnabled(imageDataArray.length > 1 && loader.logicalScreenWidth > 0 && loader.logicalScreenHeight > 0);
	
				// Display the first image in the file.
				imageDataIndex = 0;
				displayImage(imageDataArray[imageDataIndex]);
				resetScrollBars();
			}
		} catch (Exception e) {
			showErrorDialog(bundle.getString("Loading_lc"), urlname, e);
		} finally {
			shell.setCursor(null);
			imageCanvas.setCursor(crossCursor);
			waitCursor.dispose();
		}
	}

	/*
	 * Called to start a thread that draws incremental images
	 * as they are loaded.
	 */
	void incrementalThreadStart() {
		incrementalEvents = new Vector();
		incrementalThread = new Thread("Incremental") {
			public void run() {
				// Draw the first ImageData increment.
				while (incrementalEvents != null) {
					// Synchronize so we don't try to remove when the vector is null.
					synchronized (ImageAnalyzer.this) {
						if (incrementalEvents != null) {
							if (incrementalEvents.size() > 0) {
								ImageLoaderEvent event = (ImageLoaderEvent) incrementalEvents.remove(0);
								if (image != null) image.dispose();
								image = new Image(display, event.imageData);
								imageData = event.imageData;
								imageCanvasGC.drawImage(
									image,
									0,
									0,
									imageData.width,
									imageData.height,
									imageData.x,
									imageData.y,
									imageData.width,
									imageData.height);
							} else {
								yield();
							}
						}
					}
				}
				display.wake();
			}
		};
		incrementalThread.setDaemon(true);
		incrementalThread.start();
	}
	
	/*
	 * Called when incremental image data has been loaded,
	 * for example, for interlaced GIF/PNG or progressive JPEG.
	 */
	void incrementalDataLoaded(ImageLoaderEvent event) {
		// Synchronize so that we do not try to add while
		// the incremental drawing thread is removing.
		synchronized (this) {
			incrementalEvents.addElement(event);
		}
	}
	
	void menuSave() {
		if (image == null) return;
		animate = false; // stop any animation in progress

		// If the image file type is unknown, we can't 'Save',
		// so we have to use 'Save As...'.
		if (imageData.type == SWT.IMAGE_UNDEFINED || fileName == null) {
			menuSaveAs();
			return;
		}

		Cursor waitCursor = new Cursor(display, SWT.CURSOR_WAIT);
		shell.setCursor(waitCursor);
		imageCanvas.setCursor(waitCursor);
		try {
			// Save the current image to the current file.
			loader.data = new ImageData[] {imageData};
			loader.save(fileName, imageData.type);
			
		} catch (SWTException e) {
			showErrorDialog(bundle.getString("Saving_lc"), fileName, e);
		} catch (SWTError e) {
			showErrorDialog(bundle.getString("Saving_lc"), fileName, e);
		} finally {
			shell.setCursor(null);
			imageCanvas.setCursor(crossCursor);
			waitCursor.dispose();
		}
	}

	void menuSaveAs() {
		if (image == null) return;
		animate = false; // stop any animation in progress

		// Get the user to choose a file name and type to save.
		FileDialog fileChooser = new FileDialog(shell, SWT.SAVE);
		fileChooser.setFilterPath(lastPath);
		if (fileName != null) {
			String name = fileName;
			int nameStart = name.lastIndexOf(java.io.File.separatorChar);
			if (nameStart > -1) {
				name = name.substring(nameStart + 1);
			}
			fileChooser.setFileName(name);
		}
		fileChooser.setFilterExtensions(new String[] { "*.bmp", "*.gif", "*.ico", "*.jpg", "*.png" });
		fileChooser.setFilterNames(new String[] { "BMP (*.bmp)", "GIF (*.gif)", "ICO (*.ico)", "JPEG (*.jpg)", "PNG (*.png)" });
		String filename = fileChooser.open();
		lastPath = fileChooser.getFilterPath();
		if (filename == null)
			return;

		// Figure out what file type the user wants saved.
		// We need to rely on the file extension because FileDialog
		// does not have API for asking what filter type was selected.
		int filetype = determineFileType(filename);
		if (filetype == SWT.IMAGE_UNDEFINED) {
			MessageBox box = new MessageBox(shell, SWT.ICON_ERROR);
			box.setMessage(createMsg(bundle.getString("Unknown_extension"), 
			                         filename.substring(filename.lastIndexOf('.') + 1)));
			box.open();
			return;
		}
		
		if (new java.io.File(filename).exists()) {
			MessageBox box = new MessageBox(shell, SWT.ICON_QUESTION | SWT.OK | SWT.CANCEL);
			box.setMessage(createMsg(bundle.getString("Overwrite"), filename));
			if (box.open() == SWT.CANCEL)
				return;
		}
		
		Cursor waitCursor = new Cursor(display, SWT.CURSOR_WAIT);
		shell.setCursor(waitCursor);
		imageCanvas.setCursor(waitCursor);
		try {
			// Save the current image to the specified file.
			loader.data = new ImageData[] {imageData};
			loader.save(filename, filetype);
			
			// Update the shell title and file type label,
			// and use the new file.
			fileName = filename;
			shell.setText(createMsg(bundle.getString("Analyzer_on"), filename));
			typeLabel.setText(createMsg(bundle.getString("Type_string"), fileTypeString(filetype)));

		} catch (SWTException e) {
			showErrorDialog(bundle.getString("Saving_lc"), filename, e);
		} catch (SWTError e) {
			showErrorDialog(bundle.getString("Saving_lc"), filename, e);
		} finally {
			shell.setCursor(null);
			imageCanvas.setCursor(crossCursor);
			waitCursor.dispose();
		}
	}

	void menuSaveMaskAs() {
		if (image == null || !showMask) return;
		if (imageData.getTransparencyType() == SWT.TRANSPARENCY_NONE) return;
		animate = false; // stop any animation in progress

		// Get the user to choose a file name and type to save.
		FileDialog fileChooser = new FileDialog(shell, SWT.SAVE);
		fileChooser.setFilterPath(lastPath);
		if (fileName != null) fileChooser.setFileName(fileName);
		fileChooser.setFilterExtensions(new String[] { "*.bmp", "*.gif", "*.ico", "*.jpg", "*.png" });
		fileChooser.setFilterNames(new String[] { "BMP (*.bmp)", "GIF (*.gif)", "ICO (*.ico)", "JPEG (*.jpg)", "PNG (*.png)" });
		String filename = fileChooser.open();
		lastPath = fileChooser.getFilterPath();
		if (filename == null)
			return;

		// Figure out what file type the user wants saved.
		// We need to rely on the file extension because FileDialog
		// does not have API for asking what filter type was selected.
		int filetype = determineFileType(filename);
		if (filetype == SWT.IMAGE_UNDEFINED) {
			MessageBox box = new MessageBox(shell, SWT.ICON_ERROR);
			box.setMessage(createMsg(bundle.getString("Unknown_extension"), 
			                         filename.substring(filename.lastIndexOf('.') + 1)));
			box.open();
			return;
		}
		
		if (new java.io.File(filename).exists()) {
			MessageBox box = new MessageBox(shell, SWT.ICON_QUESTION | SWT.OK | SWT.CANCEL);
			box.setMessage(createMsg(bundle.getString("Overwrite"), filename));
			if (box.open() == SWT.CANCEL)
				return;
		}
		
		Cursor waitCursor = new Cursor(display, SWT.CURSOR_WAIT);
		shell.setCursor(waitCursor);
		imageCanvas.setCursor(waitCursor);
		try {
			// Save the mask of the current image to the specified file.
			ImageData maskImageData = imageData.getTransparencyMask();
			loader.data = new ImageData[] {maskImageData};
			loader.save(filename, filetype);
			
		} catch (SWTException e) {
			showErrorDialog(bundle.getString("Saving_lc"), filename, e);
		} catch (SWTError e) {
			showErrorDialog(bundle.getString("Saving_lc"), filename, e);
		} finally {
			shell.setCursor(null);
			imageCanvas.setCursor(crossCursor);
			waitCursor.dispose();
		}
	}

	void menuPrint() {
		if (image == null) return;

		try {
			// Ask the user to specify the printer.
			PrintDialog dialog = new PrintDialog(shell, SWT.NULL);
			PrinterData printerData = dialog.open();
			if (printerData == null) return;
			
			Printer printer = new Printer(printerData);
			Point screenDPI = display.getDPI();
			Point printerDPI = printer.getDPI();
			int scaleFactor = printerDPI.x / screenDPI.x;
			Rectangle trim = printer.computeTrim(0, 0, 0, 0);
			if (printer.startJob(currentName)) {
				if (printer.startPage()) {
					GC gc = new GC(printer);
					int transparentPixel = imageData.transparentPixel;
					if (transparentPixel != -1 && !transparent) {
						imageData.transparentPixel = -1;
					}
					Image printerImage = new Image(printer, imageData);
					gc.drawImage(
						printerImage,
						0,
						0,
						imageData.width,
						imageData.height,
						-trim.x,
						-trim.y,
						scaleFactor * imageData.width,
						scaleFactor * imageData.height);
					if (transparentPixel != -1 && !transparent) {
						imageData.transparentPixel = transparentPixel;
					}
					printerImage.dispose();
					gc.dispose();
					printer.endPage();
				}
				printer.endJob();
			}
			printer.dispose();
		} catch (SWTError e) {
			MessageBox box = new MessageBox(shell, SWT.ICON_ERROR);
			box.setMessage(bundle.getString("Printing_error") + e.getMessage());
			box.open();
		}
	}

	void menuReopen() {
		if (currentName == null) return;
		animate = false; // stop any animation in progress
		resetScrollBars();
		resetScaleCombos();
		Cursor waitCursor = new Cursor(display, SWT.CURSOR_WAIT);
		shell.setCursor(waitCursor);
		imageCanvas.setCursor(waitCursor);
		try {
			loader = new ImageLoader();
			long startTime = System.currentTimeMillis();
			ImageData[] newImageData;
			if (fileName == null) {
				URL url = new URL(currentName);
				InputStream stream = url.openStream();
				newImageData = loader.load(stream);
			} else {
				newImageData = loader.load(fileName);
			}
			loadTime = System.currentTimeMillis() - startTime;
			imageDataIndex = 0;
			displayImage(newImageData[imageDataIndex]);

		} catch (Exception e) {
			showErrorDialog(bundle.getString("Reloading_lc"), currentName, e);
		} finally {	
			shell.setCursor(null);
			imageCanvas.setCursor(crossCursor);
			waitCursor.dispose();
		}
	}
	
	void changeBackground() {
		String background = backgroundCombo.getText();
		if (background.equals(bundle.getString("White"))) {
			imageCanvas.setBackground(whiteColor);
		} else if (background.equals(bundle.getString("Black"))) {
			imageCanvas.setBackground(blackColor);
		} else if (background.equals(bundle.getString("Red"))) {
			imageCanvas.setBackground(redColor);
		} else if (background.equals(bundle.getString("Green"))) {
			imageCanvas.setBackground(greenColor);
		} else if (background.equals(bundle.getString("Blue"))) {
			imageCanvas.setBackground(blueColor);
		} else {
			imageCanvas.setBackground(null);
		}
	}
	
	/*
	 * Called when the ScaleX combo selection changes.