Image Show by SWT
在做一个SWT的通用DB（jdbc）工具时，为了在主画面上加个logo，用上了俺家猫猫狗狗的照片。为了展示出这些照片，这个工具成了一个副产品。
SWT的image功能是俺以前没有碰过的，第一次用的时候碰到了不少问题。比如说闪屏，比如说淡入淡出的实现。
说实话，现在的淡入淡出感觉比较完美——前图的淡出和后图的淡入非常连贯。但是这也只是个偶然的bug造成的结果，并不是俺一开始就希望得到的结果，一开始，俺希望是白淡入，黑淡出，再白淡入。最后，黑淡出并没有实现，有些遗憾。
淡入淡出功能的实现，主要是设置imagedata的alphaData。研究alphaData的时候顺便也看一点mask的文档，用mask似乎可以实现不规则窗口，以后再好好研究一下。
闪屏的问题，一直想用双缓存去解决，最后画图用的canvas只要设置成SWT.NO_BACKGROUND就OK了，于是双缓存也没有去实现。其实，双缓存也试过，不知道是俺写得不对，还是别的什么原因，双缓存也不能解决非SWT.NO_BACKGROUND的闪屏问题。
package per.chenxin.test;
import java.io.IOException;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class ImageTest ...{
public ImageTest imageTest;
public Display display;
public Canvas canvas;
Util util = null;
ImageData imageData = null;
byte[] alphaData = null;
public int fade = 0;
// public boolean bMouse易做图 = false;
// public int intMouseX = -1;
// public int intMouseY = -1;
FadeThread fadeThread = null;
public boolean isFirst = true;
public ImageTest() throws IOException ...{
imageTest = this;
util = Util.getInstance();
imageData = new ImageData(util.getInputStream());
alphaData = new byte[imageData.data.length];
imageData.alphaData = alphaData;
}
public void open() ...{
display = Display.getDefault();
final Shell shell = new Shell();
shell.addDisposeListener(new DisposeListener() ...{
public void widgetDisposed(final DisposeEvent e) ...{
try ...{
util.finalize();
} catch (Throwable e1) ...{
e1.printStackTrace();
}
}
});
shell.setText("Image Show");
//
shell.open();
canvas = new Canvas(shell, SWT.NO_BACKGROUND);
canvas.addDisposeListener(new DisposeListener() ...{
public void widgetDisposed(final DisposeEvent e) ...{
fadeThread.isActive = false;
}
});
canvas.setBackground(new Color(display, 0, 0, 0));
// canvas.addMouseMoveListener(new MouseMoveListener() {
// public void mouseMove(final MouseEvent e) {
// if ((e.x - intMouseX) * (e.x - intMouseX) + (e.y - intMouseY)
// * (e.y - intMouseY) > 10) {
// canvas.redraw();
// bMouse易做图 = true;
// intMouseX = e.x;
// intMouseY = e.y;
// }
//
// }
// });
canvas.addMouseListener(new MouseAdapter() ...{
public void mouseDown(final MouseEvent e) ...{
try ...{
if (!util.next())
util = Util.getInstance();
fadeThread.isActive = false;
fadeThread = new FadeThread(imageTest);
new Thread(fadeThread).start();
fade = 0;
imageData = new ImageData(util.getInputStream());
for (int i = 0; i < alphaData.length; i++)
alphaData[i] = (byte) fade;
imageData.alphaData = alphaData;
fade = 0;
// bMouse易做图 = true;
canvas.redraw();
} catch (IOException e1) ...{
e1.printStackTrace();
}
}
});
canvas.addPaintListener(new PaintListener() ...{
public void paintControl(final PaintEvent e) ...{
try ...{
if (imageData == null) ...{
imageData = new ImageData(util.getInputStream());
alphaData = new byte[imageData.data.length];
imageData.alphaData = alphaData;
fade = 0;
}
canvas.setSize(imageData.width, imageData.height);
shell.setSize(imageData.width, imageData.height);
if (isFirst) ...{
ImageData imageData2 = (ImageData) imageData.clone();
for (int i = 0; i < imageData2.data.length; i++) ...{
imageData2.data[i] = (byte) 255;
imageData2.alphaData[i] = (byte) 255;
}
Image image = new Image(display, imageData2);
e.gc.drawImage(image, 0, 0);
isFirst = false;
} else ...{
Image image = new Image(display, imageData);
e.gc.drawImage(image, 0, 0);
}
// if (bMouse易做图) {
// e.gc.drawOval(intMouseX - 50, intMouseY - 50, 100, 100);
// bMouse易做图 = false;
// }
} catch (IOException e1) ...{
e1.printStackTrace();
}
}
});
canvas.setBounds(0, 0, imageData.width, imageData.height);
shell.layout();
fadeThread = new FadeThread(this);
new Thread(fadeThread).start();
while (!shell.isDisposed()) ...{
if (!display.readAndDispatch())
display.sleep();
}
}
/** *//**
* Launch the application
*
* @param args
*/
public static void main(String[] args) ...{
try ...{
(new ImageTest()).open();
} catch (IOException e) ...{
e.printStackTrace();
}
}
static class FadeThread implements Runnable ...{
ImageTest imageTest;
public boolean isActive = false;
public FadeThread(ImageTest imageTest) ...{
this.imageTest = imageTest;
}
public void run() ...{
isActive = true;
while (imageTest.fade <= 255) ...{
try ...{
Thread.sleep(50);
} catch (InterruptedException e) ...{
}
if (imageTest.isFirst)
continue;
if (!isActive)
break;
for (int i = 0; i < imageTest.alphaData.length; i++)
imageTest.alphaData[i] = (byte) imageTest.fade;
// if (imageTest.intMouseX >= 0 || imageTest.intMouseY >= 0) {
// imageTest.bMouse易做图 = true;
// }
imageTest.display.asyncExec(new Runnable() ...{
public void run() ...{
imageTest.canvas.redraw();
}
});
imageTest.fade += 5;
}
isActive = false;
}
}
}
package per.chenxin.test;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
public class Util ...{
private static boolean isInited = false;
private static Util util;
private static String STR_IMAGE = "IMG_0328.zip";
public byte[] bytesZipInputStream = null;
public String strZipEntryName = null;
private ZipInputStream zipInputStream = null;
private ZipEntry zipEntry = null;
private Util() throws IOException ...{
zipInputStream = new ZipInputStream(new FileInputStream(STR_IMAGE));
zipEntry = zipInputStream.getNextEntry();
strZipEntryName = zipEntry.getName();
zipEntry = zipInputStream.getNextEntry();
if (zipEntry != null)
strZipEntryName = zipEntry.getName();
}
public InputStream getInputStream() throws IOException ...{
while (zipInputStream.available() == 0)
next();
return zipInputStream;
}
public boolean next() throws IOException ...{
zipEntry = zipInputStream.getNextEntry();
if (zipEntry == null) ...{
try ...{
finalize();
} catch (Throwable e) ...{
e.printStackTrace();
}
isInited = false;
init();
return false;
} else
strZipEntryName = zipEntry.getName();
return true;
}
public static Util getInstance() throws IOException ...{
Util.init();
return util;
}
public static void init() throws IOException ...{
if (!isInited) ...{
util = new Util();
isInited = true;
}
}
static ...{
try ...{
init();
} catch (FileNotFoundException e) ...{
e.printStackTrace();
} catch (IOException e) ...{
e.printStackTrace();
}
}
protected void finalize() throws Throwable ...{
if (zipInputStream != null) ...{
if (zipEntry != null)
zipInputStream.closeEntry();
zipInputStream.close();
}
}
public byte[] getBytesZipInputStream() throws IOException ...{
bytesZipInputStream = new byte[zipInputStream.available()];
zipInputStream.read(bytesZipInputStream);
return bytesZipInputStream;
}
public String getStrZipEntryName() ...{
return strZipEntryName;
}
}
上面代码被注释掉的部分是在mouse移动时，在mouse处加个圆圈，是用来实现放大镜功能的。但是imagedata的构造还没有完全搞清楚，放大镜功能如何实现，也想到网上找找资料，所以先注释掉了。
补充：Jsp教程,Java基础
