Android涂鸦|建立自己的手写笔画图案

自SDK 1.6开始,Android手机已支持内置Gesture Builder程序,若是被Google签署(Signed)过出厂的手机应会内置此程序,如果是程序开发人员,可在SDK文件夹里的“\android\platforms\ android\samples\GestureBuilder”找到这支程序的源代码,编译后即可生成各SDK版本可使用的Gesture Builder程序(apk)自行安装使用。

Gesture Builder提供了一手写识别的功能,让用户以类似于涂鸦的方式绘制一个手写符号,使之对应一个字符串名称,然而GestureBuilder功能虽完整,但在手写字符串的创建上却有些限制,如:制式化的建立方式、无法自行配置涂鸦区、查看手写(Gesture)以ListView来呈现等,在实际开发上稍显“复杂”了些。

下面看一下配置UI界面的activity_gesture_builder_demo.xml文件:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/white" >
    <LinearLayout
        android:id="@+id/linear_top_id"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
       android:weightSum="2"
        android:orientation="horizontal" />
       <TextView
            android:id="@+id/text_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="@dimen/padding_medium"
            android:text="@string/hello_world"
            android:textSize="18sp"
            tools:context=".GestureBuilderDemo" />
        <EditText
            android:id="@+id/edit_id"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:inputType="text" >
   /LinearLayout>
    <android.gesture.GestureOverlayView
        android:id="@+id/myGestures1"
        android:layout_width="fill_parent"
        android:layout_height="300dip"
        android:layout_below="@+id/linear_top_id"
        android:layout_marginRight="30sp"
        android:gestureColor="#8909"
        android:gestureStrokeType="multiple" />
<!--  android:gestureStrokeType="multiple"
      表示多笔支持,single则支持单一笔画
-->
    <SlidingDrawer
        android:id="@+id/slidingDreaer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:content="@+id/content"
        android:handle="@+id/handler"
        android:orientation="horizontal" >
       <ImageView
            android:id="@+id/handler"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:contentDescription="@string/app_name"
            android:src=http://blog.csdn.net/ta893115871/article/details/"@drawable/open" />
        <ListView
            android:id="@+id/content"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:choiceMode="singleChoice"
            android:background="@drawable/back"
            android:divider="@drawable/divider" >
       </ListView>
   </SlidingDrawer>
    <LinearLayout
        android:id="@+id/linear_botton_id"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:weightSum="2"
        style="@android:style/ButtonBar"
        android:orientation="horizontal" >
       <Button
            android:id="@+id/button1_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:text="@string/str_button1" />;
        <Button
            android:id="@+id/button2_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1.0"
            android:text="@string/str_button2" />
  </LinearLayout>
</RelativeLayout>

其中有一个TAG为<android.gesture. GestureOverlayView>的Widget,可称为“手写绘图区”,当中有两项较重要的属性,分别为android:layout_width设置为“fill_parent”以及android:gestureStrokeType设置为“multiple”,这表示为支持多笔画,若设置为“single”则仅支持单一笔画。

AndroidManifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.gesturebuilderdemo"
    android:versionCode="1"
    android:versionName="1.0"
android:installLocation="preferExternal"
    >
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
       <activity
            android:name=".GestureBuilderDemo"
            android:label="@string/title_activity_gesture_builder_demo" >
           <intent-filter>
                <action android:name="android.intent.action.MAIN" />
               <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        /activity>
   /application>
/manifest>

由于Gesture手写Libary文件"/sdcard/gestures"默认保存在SD存储卡中,所以需要写入External Storage的权限。

再看java文件中看几个函数:
Gesture对象是自GestureOverlayView.getGesture() 所取得的手写对象;GestureLibraries为保存手写背后所包含的意义(String),本范例利用GestureLibraries.fromFile()方法来加载预设的Gesture文件,倘若默认手机的SD存储卡中尚未创建Gesture手写数据文件,此程序也会处理创建新文件的工作。此外,程序中举例应用了GestureLibraries.addGesture()新建手写数据、GestureLibraries.save()保存写入手写数据GestureLibraries.load()加载手写数据、GestureLibraries. removeGesture()删除手写数据等方法。

GestureBuilderDemo.java

package com.example.gesturebuilderdemo;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.GestureOverlayView.OnGestureListener;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SlidingDrawer;
import android.widget.SlidingDrawer.OnDrawerCloseListener;
import android.widget.SlidingDrawer.OnDrawerOpenListener;
import android.widget.Toast;
public class GestureBuilderDemo extends Activity {
private static final  String TAG="GestureBuilderDemo";
private Button mButton1, mButton2;
private GestureOverlayView mGestureOverlayView;//手写绘制区
private EditText mEditText;
private Gesture ges;
private GestureLibrary lib;
private String gesPath;
// ----------------------------
private ImageView mImageView;//拉动式抽屉
private SlidingDrawer mDrawer;//拉动式抽屉的手柄
private ListView mListView;//拉动式抽屉的内容
private List<String> gesNames = new ArrayList<String>();//保存手写的名称集合
private List<Bitmap> gesPics = new ArrayList<Bitmap>();//保存转换为手写的图片的集合
//------------------- -------
private LinearLayout layout_bottom;//底部的2个<A class=relatedlink  target=_blank>按钮</A><A class=relatedlink  target=_blank>布局</A>
private LinearLayout layout_top;//顶部的2个按钮布局
private MyListAdapter adapter;//适配器
@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  /* 查看SDCard是否存在 */
  setContentView(R.layout.activity_gesture_builder_demo);
  if (!Environment.MEDIA_MOUNTED.equals(Environment
    .getExternalStorageState())) {
   Toast.makeText(this, "SDCard不存在!", Toast.LENGTH_SHORT).show();
   this.finish();
  }
  /* 取得系统默认的GestureLibrary的文件路径 */
  gesPath = new File(Environment.getExternalStorageDirectory(),
    "gestures").getAbsolutePath();
  mButton1 = (Button) this.findViewById(R.id.button1_id);
  mButton2 = (Button) this.findViewById(R.id.button2_id);
  mGestureOverlayView = (GestureOverlayView) this
    .findViewById(R.id.myGestures1);
  mEditText = (EditText) this.findViewById(R.id.edit_id);
  mButton1.setEnabled(false);
  mImageView = (ImageView) this.findViewById(R.id.handler);
  mDrawer = (SlidingDrawer) this.findViewById(R.id.slidingDreaer);
  mListView = (ListView) this.findViewById(R.id.content);
  mEditText.setOnKeyListener(keyListener);
  mGestureOverlayView.addOnGestureListener(onGestureListener);
  mButton1.setOnClickListener(listener1);
  mButton2.setOnClickListener(listener2);
  layout_bottom=(LinearLayout)this.findViewById(R.id.linear_botton_id);
  layout_top=(LinearLayout)this.findViewById(R.id.linear_top_id);
  adapter=new MyListAdapter(this,gesNames,gesPics);
  getExitGesture();//读取SD卡中的/sdcard/gestures里建立的手写,并显示在ListView中
  mListView.setAdapter(adapter);
  mListView.setOnItemClickListener(list_listener);
  mDrawer.setOnDrawerOpenListener(onDrawerOpenListener_open);
  mDrawer.setOnDrawerCloseListener(onDrawerCloseListener_close);
}
OnItemClickListener  list_listener=new OnItemClickListener(){
  public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
    long arg3) {
   // TODO Auto-generated method stub
   Toast.makeText(GestureBuilderDemo.this, "GestureName:"+gesNames.get(arg2),
     Toast.LENGTH_SHORT).show();
  }
};
//抽屉打开
OnDrawerOpenListener  onDrawerOpenListener_open=new OnDrawerOpenListener(){
  public void onDrawerOpened() {
   // TODO Auto-generated method stub
   mImageView.setImageResource(R.drawable.close);
   layout_bottom.setVisibility(View.GONE);
   layout_top.setVisibility(View.GONE);
   mGestureOverlayView.setVisibility(View.GONE);
   getExitGesture();
  }
};
//抽屉关闭
OnDrawerCloseListener  onDrawerCloseListener_close=new OnDrawerCloseListener(){
  public void onDrawerClosed() {
   // TODO Auto-generated method stub
   mImageView.setImageResource(R.drawable.open);
   layout_bottom.setVisibility(View.VISIBLE);
   layout_top.setVisibility(View.VISIBLE);
   mGestureOverlayView.setVisibility(View.VISIBLE);
  }
};
//读取SD卡中的/sdcard/gestures里建立的手写,并显示在ListView中
public void getExitGesture() {
  Log.i(TAG, "getExitGesture()");
  gesNames.clear();
  gesPics.clear();
  File f = new File(gesPath);
  lib = GestureLibraries.fromFile(f);
  if (f.exists()) {
   if (!lib.load()) {
    Toast.makeText(GestureBuilderDemo.this, "加载失败!!",
      Toast.LENGTH_SHORT).show();
   } else {
    Object\[\] obj = lib.getGestureEntries().toArray();
    for (int i = 0; i < obj.length; i++) {
     ArrayList<Gesture> al = lib.getGestures(obj\[i\].toString());
    // Log.i(TAG, "i="+i);
     for (int j = 0; j < al.size(); j++) {
    //  Log.i(TAG, "j="+j);
    //  Log.i(TAG, "obj\[i\].toString()==="+obj\[i\].toString());
      // 手写名称
      gesNames.add(obj\[i\].toString());
      Gesture gs = (Gesture) al.get(j);
      //将手写转成Bitmap图片
      gesPics.add(gs.toBitmap(50, 50, 12, Color.MAGENTA));
     }
    }
   }
  } else {
   Toast.makeText(GestureBuilderDemo.this, "文件不存在!",
     Toast.LENGTH_SHORT).show();
  }
  adapter.notifyDataSetChanged();
}
OnGestureListener onGestureListener = new OnGestureListener() {
  public void onGesture(GestureOverlayView overlay, MotionEvent event) {
   // TODO Auto-generated method stub
  }
  public void onGestureCancelled(GestureOverlayView overlay,
    MotionEvent event) {
   // TODO Auto-generated method stub
  }
  public void onGestureEnded(GestureOverlayView overlay, MotionEvent event) {
   // TODO Auto-generated method stub
   ges = overlay.getGesture();
   if (ges != null
     && mEditText.getText().toString().trim().length() != 0) {
    mButton1.setEnabled(true);
   }
  }
  public void onGestureStarted(GestureOverlayView overlay,
    MotionEvent event) {
   // TODO Auto-generated method stub
   ges = null;
   mButton1.setEnabled(false);
  }
};
OnKeyListener keyListener = new OnKeyListener() {
  public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
   // TODO Auto-generated method stub
   if (ges != null
     && mEditText.getText().toString().trim().length() != 0) {
    mButton1.setEnabled(true);
   } else {
    mButton1.setEnabled(false);
   }
   return false;
  }
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
  getMenuInflater().inflate(R.menu.activity_gesture_builder_demo, menu);
  return true;
}
OnClickListener listener1 = new OnClickListener() {
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   String gestureName = mEditText.getText().toString().trim();
   lib = GestureLibraries.fromFile(gesPath);
   File f = new File(gesPath);
   if (!f.exists()) {
    /* 文件不存在就直接写入 */
    lib.addGesture(gestureName, ges);
    if (lib.save()) {
     mEditText.setText("");
     mGestureOverlayView.clear(true);
     mButton1.setEnabled(false);
     Toast.makeText(GestureBuilderDemo.this,
       "保存成功,路径为:" + gesPath, Toast.LENGTH_SHORT).show();
    } else {
     Toast.makeText(GestureBuilderDemo.this, "保存失败!",
       Toast.LENGTH_SHORT).show();
    }
   } else {
    // 文件存在时,先读取已经存在的Gesture
    if (lib.load()) {
     /* 如果Library中存在相同名称,则先将其移除再写入 */
     Set<String> set = lib.getGestureEntries();
     if (set.contains(gestureName)) {
      ArrayList<Gesture> list = lib.getGestures(gestureName);
      for (int i = 0; i < list.size(); i++) {
       //删除手写数据
       lib.removeGesture(gestureName, list.get(i));
      }
     }
     //新增手写数据
     lib.addGesture(gestureName, ges);
     // 保存写入手写数据
     if (lib.save()) {
      mEditText.setText("");
      mGestureOverlayView.clear(true);
      mButton1.setEnabled(false);
      Toast.makeText(GestureBuilderDemo.this,
        "保存成功,路径为:" + gesPath, Toast.LENGTH_SHORT)
        .show();
     } else {
      Toast.makeText(GestureBuilderDemo.this, "保存失败!",
        Toast.LENGTH_SHORT).show();
     }
    } else {
     Toast.makeText(GestureBuilderDemo.this, "加载失败!",
       Toast.LENGTH_SHORT).show();
    }
   }
   mDrawer.toggle();
  }
};
OnClickListener listener2 = new OnClickListener() {
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   mEditText.setText("");
   mGestureOverlayView.clear(true);
   mButton1.setEnabled(false);
  }
};
}

ListView的适配器文件:

package com.example.gesturebuilderdemo;
import java.util.List;
import android.content.Context;
import android.graphics.Bitmap;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class MyListAdapter extends BaseAdapter {
private Context mContext;
private List<String> gesNames ;
private List<Bitmap> gesPics ;
public MyListAdapter(Context mContext,List<String> gesNames,List<Bitmap> gesPics )
{
  this.mContext=mContext;
  this.gesNames=gesNames;
  this.gesPics=gesPics;
}
public int getCount() {
  // TODO Auto-generated method stub
  return gesNames.size();
}
public Object getItem(int arg0) {
  // TODO Auto-generated method stub
  return gesNames.get(arg0);
}
public long getItemId(int position) {
  // TODO Auto-generated method stub
  return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
  // TODO Auto-generated method stub
  convertView= LayoutInflater.from(mContext).inflate(R.layout.list, null);
  ImageView img=(ImageView)convertView.findViewById(R.id.img_id);
  img.setImageBitmap(gesPics.get(position));
  TextView text=(TextView)convertView.findViewById(R.id.text_id);
  text.setText(gesNames.get(position));
  return convertView;
}
}

ListView的布局配置文件:

<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
   <ImageView
        android:id="@+id/img_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:contentDescription="@string/app_name" />
    <TextView
        android:id="@+id/text_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@+id/img_id"
        android:lines="1"
        android:textColor="#f699"
        android:textSize="20sp"
        android:textStyle="bold" />
</RelativeLayout>

文件中有详细说明,不多说了。
当建立完手写和输入名称后自动把添加按钮Enable,所用的监听器为: mEditText.setOnKeyListener(keyListener);
点击添加按钮后悔自动打开抽屉获取以ListView显示在抽屉中。

界面如下所示:

EyeAndroid.com47361022350301.png

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