Android的gesture的识别和自定义gesture

今天起介绍下和手势和多点触摸相关的知识。。。。。。

先上个一道菜，手势的识别。。。。。

java.lang.Object
   ↳	android.view.View
 	   ↳	android.view.ViewGroup
 	 	   ↳	android.widget.FrameLayout
 	 	 	   ↳	android.gesture.GestureOverlayView

介绍下GestureOverlayView，这个透明的view就是让你在上面画手势用的，可叠在其他View上面。

和这个类相关的还有三个接口，分别是

GestureOverlayView.OnGestureListener；

GestureOverlayView.OnGesturePerformedListener（作用：根据在GestureOverlayView上画的手势来识别是否匹配手势库里的手势）；

GestureOverlayView.OnGesturingListener.

GestureOverlayView的xml的属性介绍：

android:gestureStrokeType

设置手势的笔画数，它有两个值，GESTURE_STROKE_TYPE_MULTIPLE（多笔），GESTURE_STROKE_TYPE_SINGLE（一笔）

public final class GestureLibraries

 static GestureLibrary 	fromFile(File path) 
 static GestureLibrary 	fromFile(String path) 
 static GestureLibrary 	fromPrivateFile(Context context, String name) 
 static GestureLibrary 	fromRawResource(Context context, int resourceId)

想从SD卡或者raw的资源中直接加载手势；

下面介绍下手势的识别功能，先上代码：

GestureIdentifyDemoActivity.xml

package com.potato;

import java.util.ArrayList;

import android.app.Activity;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.Prediction;
import android.os.Bundle;
import android.widget.Toast;

public class GestureIdentifyDemoActivity extends Activity {
	// 手势库
	GestureLibrary mGestureLib;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		// 手势画板
		GestureOverlayView gestures = (GestureOverlayView) findViewById(R.id.gesture_overlay_view_test);
		// 手势识别的监听器
		gestures.addOnGesturePerformedListener(new GestureOverlayView.OnGesturePerformedListener() {	// 注1

			@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);						// 注3
											
				if (predictions.size() > 0) {
					Prediction prediction = (Prediction) predictions.get(0);
					// 匹配的手势
					if (prediction.score > 1.0) {
						Toast.makeText(GestureIdentifyDemoActivity.this,
								prediction.name, Toast.LENGTH_SHORT).show();
					}
				}

			}
		});
		// 从raw中加载已经有的手势库
		mGestureLib = GestureLibraries.fromRawResource(this, R.raw.gestures);		// 注2
		if (!mGestureLib.load()) {
			finish();
		}

	}
}

注1：

gestures.addOnGesturePerformedListener(new GestureOverlayView.OnGesturePerformedListener()

手势识别的监听器。。。。

注2：

mGestureLib = GestureLibraries.fromRawResource(this, R.raw.gestures);

从res/raw/加载gestures手势这个文件

注3：

ArrayList<Prediction> predictions = mGestureLib.recognize(gesture);

从手势库中识别出和在GestureOverlayView所画的手势；

mian.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="输入手势：" />
    <!-- 注意  android.gesture.要加，否则报错，估计是找不到包-->
    <android.gesture.GestureOverlayView
        android:id="@+id/gesture_overlay_view_test"
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="1.0"
        android:gestureStrokeType="multiple" />

</LinearLayout>

这里要注意：android.gesture.GestureOverlayView这里的不能用GestureOverlayView

下面介绍如何向手势库中增加自定义的手势：

上代码：

GestureBuilderDemoActivity.java

package com.potato;

import java.io.File;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Environment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

public class GestureBuilderDemoActivity extends Activity {

	private static final int STATUS_SUCCESS = 0;
	private static final int STATUS_CANCELLED = 1;
	private static final int STATUS_NO_STORAGE = 2;
	private static final int STATUS_NOT_LOADED = 3;

	private static final int REQUEST_NEW_GESTURE = 1;

	// 存放手势的文件
	private final File mStoreFile = new File(
			Environment.getExternalStorageDirectory(), "gestures");

	private GesturesAdapter mAdapter;
	private static GestureLibrary mGestureLib;

	private TextView mTvEmpty;
	Button mBtnAddGesture;
	Button mBtnIdentify;

	Resources mRes;
	ListView mListViewGesture;

	// 宽度、高度
	private int mThumbnailSize;
	// 密度
	private int mThumbnailInset;
	// 颜色
	private int mPathColor;

	static GestureLibrary getStore() {
		return mGestureLib;
	}

	/**
	 * 手势排序
	 */
	private final Comparator<NamedGesture> mSorter = new Comparator<NamedGesture>() {			
		public int compare(NamedGesture object1, NamedGesture object2) {
			return object1.name.compareTo(object2.name);
		}
	};

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		mRes = getResources();

		mBtnAddGesture = (Button) findViewById(R.id.addButton);
		mBtnIdentify = (Button) findViewById(R.id.reloadButton);

		mPathColor = mRes.getColor(R.color.gesture_color);
		mThumbnailInset = (int) mRes
				.getDimension(R.dimen.gesture_thumbnail_inset);
		mThumbnailSize = (int) mRes
				.getDimension(R.dimen.gesture_thumbnail_size);

		mListViewGesture = (ListView) findViewById(android.R.id.list);
		mAdapter = new GesturesAdapter(this);
		mListViewGesture.setAdapter(mAdapter);

		if (mGestureLib == null) {
			mGestureLib = GestureLibraries.fromFile(mStoreFile);				// 注1
		}
		mTvEmpty = (TextView) findViewById(android.R.id.empty);
		loadGestures();															

		if (mListViewGesture.getAdapter().isEmpty()) {
			mListViewGesture.setEmptyView(mTvEmpty);
			mBtnAddGesture.setEnabled(false);
		} else {
			mBtnAddGesture.setEnabled(true);
		}
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		super.onActivityResult(requestCode, resultCode, data);

		if (resultCode == RESULT_OK) {
			switch (requestCode) {
			case REQUEST_NEW_GESTURE:
				loadGestures();
				break;
			}
		}
	}

	/**
	 * 识别手势
	 */
	@SuppressWarnings({ "UnusedDeclaration" })
	public void identifyGestures(View v) {
		Intent intent = new Intent(this, GestureIdentifyDemoActivity.class);
		startActivity(intent);
	}

	/**
	 * 创建手势
	 * @param v
	 */
	@SuppressWarnings({ "UnusedDeclaration" })
	public void addGesture(View v) {
		Intent intent = new Intent(this, CreateGestureActivity.class);
		startActivityForResult(intent, REQUEST_NEW_GESTURE);
	}

	/**
	 * 加载手势
	 * @return
	 */
	private int loadGestures() {
		if (!Environment.MEDIA_MOUNTED.equals(Environment
				.getExternalStorageState())) {
			return STATUS_NO_STORAGE;
		}

		final GestureLibrary gestureLib = mGestureLib;

		mAdapter.clear();
		if (gestureLib.load()) {										// 注2
			for (String name : gestureLib.getGestureEntries()) {

				for (Gesture gesture : gestureLib.getGestures(name)) {
					final Bitmap bitmap = gesture.toBitmap(mThumbnailSize,			// 注3
							mThumbnailSize, mThumbnailInset, mPathColor);
					final NamedGesture namedGesture = new NamedGesture();
					namedGesture.gesture = gesture;
					namedGesture.name = name;

					mAdapter.addBitmap(namedGesture.gesture.getID(), bitmap);
					mAdapter.add(namedGesture);
				}
			}
			mAdapter.sort(mSorter);							// 注4
			mAdapter.notifyDataSetChanged();
			return STATUS_SUCCESS;
		}

		return STATUS_NOT_LOADED;
	}

	static class NamedGesture {
		String name;
		Gesture gesture;
	}

	private class GesturesAdapter extends ArrayAdapter<NamedGesture> {
		private final LayoutInflater mInflater;
		private final Map<Long, Drawable> mThumbnails = Collections
				.synchronizedMap(new HashMap<Long, Drawable>());

		public GesturesAdapter(Context context) {
			super(context, 0);
			mInflater = (LayoutInflater) context
					.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
		}

		void addBitmap(Long id, Bitmap bitmap) {
			mThumbnails.put(id, new BitmapDrawable(bitmap));
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			if (convertView == null) {
				convertView = mInflater.inflate(R.layout.list_item_gesture,
						parent, false);
			}

			final NamedGesture gesture = getItem(position);
			final TextView label = (TextView) convertView;

			label.setTag(gesture);
			label.setText(gesture.name);
			label.setCompoundDrawablesWithIntrinsicBounds(
					mThumbnails.get(gesture.gesture.getID()), null, null, null);

			return convertView;
		}
	};
}

注1

mGestureLib = GestureLibraries.fromFile(mStoreFile);

从SD卡中加载已有的手势；

注2

gestureLib.load()

从手势库加载手势

注3

final Bitmap bitmap = gesture.toBitmap(mThumbnailSize,			// 注3
							mThumbnailSize, mThumbnailInset, mPathColor);

把手势转换成bitmap

注4

排序

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#009966"
    android:orientation="vertical" >

    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1.0" />

    <LinearLayout
        style="@android:style/ButtonBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/addButton"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:enabled="false"
            android:onClick="addGesture"
            android:text="button_add" />

        <Button
            android:id="@+id/reloadButton"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="identifyGestures"
            android:text="button_identify" />

    </LinearLayout>

</LinearLayout>

创建手势

CreateGestureActivity.java

package com.potato;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.MotionEvent;
import android.gesture.GestureOverlayView;
import android.gesture.Gesture;
import android.gesture.GestureLibrary;
import android.widget.TextView;
import android.widget.Toast;

import java.io.File;

public class CreateGestureActivity extends Activity {
	private static final float LENGTH_THRESHOLD = 120.0f;

	private Gesture mGesture;
	private View mDoneButton;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		setContentView(R.layout.create_gesture);

		mDoneButton = findViewById(R.id.done);

		GestureOverlayView overlay = (GestureOverlayView) findViewById(R.id.gestures_overlay);
		overlay.addOnGestureListener(new GesturesProcessor());
	}

	@Override
	protected void onSaveInstanceState(Bundle outState) {
		super.onSaveInstanceState(outState);

		if (mGesture != null) {
			outState.putParcelable("gesture", mGesture);
		}
	}

	@Override
	protected void onRestoreInstanceState(Bundle savedInstanceState) {
		super.onRestoreInstanceState(savedInstanceState);

		mGesture = savedInstanceState.getParcelable("gesture");
		if (mGesture != null) {
			final GestureOverlayView overlay = (GestureOverlayView) findViewById(R.id.gestures_overlay);
			overlay.post(new Runnable() {
				public void run() {
					overlay.setGesture(mGesture);
				}
			});

			mDoneButton.setEnabled(true);
		}
	}

	/**
	 * 增加手势的按钮
	 * @param v
	 */
	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("输入gesture的名字！");
				return;
			}
			
			// 把手势增加到手势库
			final GestureLibrary store = GestureBuilderDemoActivity.getStore();			// 注1
			store.addGesture(name.toString(), mGesture);
			store.save();

			setResult(RESULT_OK);

			final String path = new File(
					Environment.getExternalStorageDirectory(), "gestures")
					.getAbsolutePath();
			Toast.makeText(this, "保存成功" + path, Toast.LENGTH_LONG).show();
		} else {
			setResult(RESULT_CANCELED);
		}

		finish();

	}

	/**
	 * 取消手势
	 * @param v
	 */
	public void cancelGesture(View v) {
		setResult(RESULT_CANCELED);
		finish();
	}

	/**
	 * 手势监听着
	 * @author Administrator
	 *
	 */
	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) {
			// 获取在GestureOverlayView手势
			mGesture = overlay.getGesture();										// 注2
			if (mGesture.getLength() < LENGTH_THRESHOLD) {
				overlay.clear(false);
			}
			mDoneButton.setEnabled(true);
		}

		public void onGestureCancelled(GestureOverlayView overlay,
				MotionEvent event) {
		}
	}
}

注1

final GestureLibrary store = GestureBuilderDemoActivity.getStore();			// 注1
			store.addGesture(name.toString(), mGesture);
			store.save();

手势增加到手势库

注2

获取在GestureOverlayView手势

create_gesture.xml\

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"
    android:layout_height="match_parent"
    
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
    
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="6dip"
            android:text="prompt_gesture_name"
            android:textAppearance="?android:attr/textAppearanceMedium" />
        
        <EditText
            android:id="@+id/gesture_name"
            android:layout_width="0dip"
            android:layout_weight="1.0"
            android:layout_height="wrap_content"
            android:maxLength="40"
            android:singleLine="true" />

    </LinearLayout>
    
    <android.gesture.GestureOverlayView
        android:id="@+id/gestures_overlay"
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="1.0"
        android:gestureStrokeType="multiple" />

    <LinearLayout
        style="@android:style/ButtonBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/done"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:enabled="false"
            android:onClick="addGesture"
            android:text="button_done" />
    
        <Button
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="cancelGesture"
            android:text="button_discard" />
    
    </LinearLayout>
    
</LinearLayout>

注意，不要忘记，写入手势时，一定要增加权限，写入sd卡

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

有问题，请留言或者发邮件

[e-mail]

源代码下载地址：http://download.csdn.net/detail/alex0203/3868687