源码:http://files.cnblogs.com/android100/gesture.builder.zip
使用一些浏览器或者输入法应用时会有一些手势操作,还可以自定义手势。这些神奇的操作是怎么做的呢?这一篇重点记录手势的识别和创建。这篇的内容使用到的是android.gesture包,具体的例子参考的是Sample中GestureBuilder程序。
1、手势创建
手势创建主要用到GestureOverlayView和GestureLibrary。GestureOverlayView的父类为android.widget.FrameLayout,是手势绘图区。GestureLibrary类主要对手势进行保存、删除等操作的,存放手势的仓库。下面给出创建手势的例子,如下图,可以定义如图手势打开csdn.net
1.1、创建绘图区
- GestureOverlayView overlay = (GestureOverlayView) findViewById(R.id.gestures_overlay);
- overlay.setGestureStrokeType(GestureOverlayView.GESTURE_STROKE_TYPE_MULTIPLE);
- overlay.setFadeOffset(2000); //多笔画每两次的间隔时间
- overlay.setGestureColor(Color.CYAN);//画笔颜色
- overlay.setGestureStrokeWidth(6);//画笔粗细值
- overlay.addOnGestureListener(new GesturesProcessor());
1.2、监听绘制
- private class GesturesProcessor implements GestureOverlayView.OnGestureListener {
- public void onGestureStarted(GestureOverlayView overlay, MotionEvent event) {
- mDoneButton.setEnabled(false);
- mGesture = null;
- }
- public void onGesture(GestureOverlayView overlay, MotionEvent event) {
- }
- public void onGestureEnded(GestureOverlayView overlay, MotionEvent event) {
- mGesture = overlay.getGesture();
- if (mGesture.getLength() < LENGTH_THRESHOLD) {
- overlay.clear(false);
- }
- mDoneButton.setEnabled(true);
- }
- public void onGestureCancelled(GestureOverlayView overlay, MotionEvent event) {
- }
- }
1.3、保存手势
- public void addGesture(View v) {
- if (mGesture != null) {
- final TextView input = (TextView) findViewById(R.id.gesture_name);
- final CharSequence name = input.getText();
- if (name.length() == 0) {
- input.setError(getString(R.string.error_missing_name));
- return;
- }
- /**
- * 获取手势库
- * private final File mStoreFile = new File(Environment.getExternalStorageDirectory(), "gestures");
- * GestureLibrary sStore = GestureLibraries.fromFile(mStoreFile);
- *
- */
- final GestureLibrary store = GestureBuilderActivity.getStore();
- store.addGesture(name.toString(), mGesture);
- store.save();
- setResult(RESULT_OK);
- final String path = new File(Environment.getExternalStorageDirectory(),
- "gestures").getAbsolutePath();
- Toast.makeText(this, getString(R.string.save_success, path), Toast.LENGTH_LONG).show();
- } else {
- setResult(RESULT_CANCELED);
- }
- finish();
- }
2、手势识别
手势识别也是经过创建绘图区、监听绘制、比对结果三个过程,这里直接给出代码。
- public class GesturePerformedActivity extends Activity {
- private final File mStoreFile = new File(
- Environment.getExternalStorageDirectory(), "gestures");
- // 手势库
- GestureLibrary mGestureLib;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- // TODO Auto-generated method stub
- super.onCreate(savedInstanceState);
- setContentView(R.layout.gesture_perform);
- // 手势画板
- GestureOverlayView gestures = (GestureOverlayView) findViewById(R.id.gestures_overlay);
- gestures.setGestureStrokeType(GestureOverlayView.GESTURE_STROKE_TYPE_MULTIPLE);
- gestures.setFadeOffset(2000); // 多笔画每两次的间隔时间
- gestures.setGestureColor(Color.CYAN);// 画笔颜色
- gestures.setGestureStrokeWidth(6);// 画笔粗细值
- // 手势识别的监听器
- gestures.addOnGesturePerformedListener(new GestureOverlayView.OnGesturePerformedListener() {
- @Override
- public void onGesturePerformed(GestureOverlayView overlay,
- Gesture gesture) {
- // 从手势库中查询匹配的内容,匹配的结果可能包括多个相似的结果,匹配度高的结果放在最前面
- ArrayList<Prediction> predictions = mGestureLib
- .recognize(gesture);
- if (predictions.size() > 0) {
- Prediction prediction = (Prediction) predictions.get(0);
- // 匹配的手势
- if (prediction.score > 1.0) { // 越匹配score的值越大,最大为10
- Toast.makeText(GesturePerformedActivity.this,
- prediction.name, Toast.LENGTH_SHORT).show();
- }
- }
- }
- });
- if (mGestureLib == null) {
- mGestureLib = GestureLibraries.fromFile(mStoreFile);
- mGestureLib.load();
- }
- }
- }
最后还有点问题,就是多笔画识别问题,这里没有很好的解决,使用OnGesturePerformedListener接听结束,有的多笔画会识别失败,尤其简单的横线竖线组合,复杂的却没有问题。如果使用GestureOverlayView.OnGestureListener监听结束,每一笔画都会调用,不能处理未知笔画数的识别。如果哪位同学完美解决了多笔画问题,请多指教,谢谢。