Android 手势相关(二)
本篇文章继续记录下android 手势相关的内容.
1: GestureOverlayView简介
GestureOverlayView是Android中的一个视图组件，用于捕捉和处理手势操作.
GestureOverlayView的主要用途:
- 手势识别: 通过GestureOverlayView,保存一些手势,并堆用户手势操作进行识别匹配.
- 手势绘制: 我们还可以在GestureOverlayView绘制,并保存绘制路径或者手势.
- 手势交互: 我们可以监听手势的开始,结束等事件.
本文主要介绍的是手势识别这块,实现的效果就是设置手势的名称, 保存手势, 绘制手势判断是否匹配.
2: 布局
界面布局主要有几块:
- EditText 用于设置手势名称
- btn1用于设置保存手势动作
- btn2用于设置匹配手势动作
- GestureOverlayView用于手势绘制.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".GestureActivity">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:hint="请输入保存手势的名称"
android:id="@+id/edit_name"
/>
<Button
android:id="@+id/btn_save"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="保存手势"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/edit_name"
/>
<Button
android:id="@+id/btn_compare"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="匹配手势"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/btn_save" />
<android.gesture.GestureOverlayView
android:id="@+id/gesture"
android:layout_width="300dp"
android:layout_height="300dp"
android:background="#aaaaaa"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/btn_compare" />
</androidx.constraintlayout.widget.ConstraintLayout>
GestureOverlayView在xml定义的属性可以查看下attrs.xml.
<!-- GestureOverlayView specific attributes. These attributes are used to configure
a GestureOverlayView from XML. -->
<declare-styleable name="GestureOverlayView">
<!-- Width of the stroke used to draw the gesture. -->
<attr name="gestureStrokeWidth" format="float" />
<!-- Color used to draw a gesture. -->
<attr name="gestureColor" format="color" />
<!-- Color used to draw the user's strokes until we are sure it's a gesture. -->
<attr name="uncertainGestureColor" format="color" />
<!-- Time, in milliseconds, to wait before the gesture fades out after the user
is done drawing it. -->
<attr name="fadeOffset" format="integer" />
<!-- Duration, in milliseconds, of the fade out effect after the user is done
drawing a gesture. -->
<attr name="fadeDuration" format="integer" />
<!-- Defines the type of strokes that define a gesture. -->
<attr name="gestureStrokeType">
<!-- A gesture is made of only one stroke. -->
<enum name="single" value="0" />
<!-- A gesture is made of multiple strokes. -->
<enum name="multiple" value="1" />
</attr>
<!-- Minimum length of a stroke before it is recognized as a gesture. -->
<attr name="gestureStrokeLengthThreshold" format="float" />
<!-- Squareness threshold of a stroke before it is recognized as a gesture. -->
<attr name="gestureStrokeSquarenessThreshold" format="float" />
<!-- Minimum curve angle a stroke must contain before it is recognized as a gesture. -->
<attr name="gestureStrokeAngleThreshold" format="float" />
<!-- Defines whether the overlay should intercept the motion events when a gesture
is recognized. -->
<attr name="eventsInterceptionEnabled" format="boolean" />
<!-- Defines whether the gesture will automatically fade out after being recognized. -->
<attr name="fadeEnabled" format="boolean" />
<!-- Indicates whether horizontal (when the orientation is vertical) or vertical
(when orientation is horizontal) strokes automatically define a gesture. -->
<attr name="orientation" />
</declare-styleable>
这里我只用到了gestureStrokeWidth,gestureColor两个属性,并且是在代码中设置的.
3: GestureLibrary对象
GestureLibrary 是android 中用于保存和管理手势的类. 源码很简单,具体的方法有兴趣的都去试下
public abstract class GestureLibrary {
protected final GestureStore mStore;
protected GestureLibrary() {
mStore = new GestureStore();
}
public abstract boolean save();
public abstract boolean load();
public boolean isReadOnly() {
return false;
}
/** @hide */
public Learner getLearner() {
return mStore.getLearner();
}
public void setOrientationStyle(int style) {
mStore.setOrientationStyle(style);
}
public int getOrientationStyle() {
return mStore.getOrientationStyle();
}
public void setSequenceType(int type) {
mStore.setSequenceType(type);
}
public int getSequenceType() {
return mStore.getSequenceType();
}
public Set<String> getGestureEntries() {
return mStore.getGestureEntries();
}
public ArrayList<Prediction> recognize(Gesture gesture) {
return mStore.recognize(gesture);
}
public void addGesture(String entryName, Gesture gesture) {
mStore.addGesture(entryName, gesture);
}
public void removeGesture(String entryName, Gesture gesture) {
mStore.removeGesture(entryName, gesture);
}
public void removeEntry(String entryName) {
mStore.removeEntry(entryName);
}
public ArrayList<Gesture> getGestures(String entryName) {
return mStore.getGestures(entryName);
}
}
创建对象:
gestureLibrary = GestureLibraries.fromFile("sdcard/gesture");
根据路径创建gestureLibrary创建对象. 这里无需关注文件是否存在,save方法会有判断:
public boolean save() {
if (!mStore.hasChanged()) return true;
final File file = mPath;
final File parentFile = file.getParentFile();
if (!parentFile.exists()) {
if (!parentFile.mkdirs()) {
return false;
}
}
boolean result = false;
try {
//noinspection ResultOfMethodCallIgnored
file.createNewFile();
mStore.save(new FileOutputStream(file), true);
result = true;
} catch (FileNotFoundException e) {
Log.d(LOG_TAG, "Could not save the gesture library in " + mPath, e);
} catch (IOException e) {
Log.d(LOG_TAG, "Could not save the gesture library in " + mPath, e);
}
return result;
}
由于是文件操作,权限不能忘记:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
4: GestureOverlayView
GestureOverlayView提供了三个接口实现:
- addOnGestureListener(OnGestureListener listener)
- addOnGesturePerformedListener(OnGesturePerformedListener listener)
- addOnGesturingListener(OnGesturingListener listener)
这里我们使用addOnGesturePerformedListener,将手势识别器与手势监听器关联:
gestureOverlayView.setGestureColor(R.color.teal_200);
gestureOverlayView.setGestureStrokeWidth(5);
gestureOverlayView.addOnGesturePerformedListener(new GestureOverlayView.OnGesturePerformedListener() {
@Override
public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
//处理手势执行
}
}
onGesturePerformed方法中我们做两个操作:
- 保存手势
- 判断手势匹配
保存手势的操作:
根据onGesturePerformed回调的gesture,我们调用gestureLibrary.addGesture添加手势,并调用gestureLibrary.save()进行保存.
gestureLibrary.addGesture(editText.getText().toString(), gesture);
if (gestureLibrary.save()) {
Toast.makeText(GestureActivity.this, "保存手势成功", Toast.LENGTH_LONG).show();
}else{
Toast.makeText(GestureActivity.this, "保存手势失败", Toast.LENGTH_LONG).show();
}
判断匹配:
调用recognize方法,传入一个手势参数,返回与参数手势最匹配的手势,
Prediction.score是用来表示手势匹配的置信度或相似度的指标,
它是一个浮点数，范围通常是0到10之间，表示匹配的程度.
ArrayList<Prediction> recognize = gestureLibrary.recognize(gesture);
Prediction prediction = recognize.get(0);
if (prediction.score >= 2) {
Toast.makeText(GestureActivity.this, prediction.name + "匹配成功", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(GestureActivity.this, prediction.name + "匹配失败", Toast.LENGTH_SHORT).show();
}
完整的代码如下:
public class GestureActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = "GestureActivity";
private GestureOverlayView gestureOverlayView;
private Button btnSave, btnCompare;
private int status = 0; // 1:保存手势 2: 手势比较
private GestureLibrary gestureLibrary;
private EditText editText;
@SuppressLint("ResourceAsColor")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gesture);
gestureOverlayView = findViewById(R.id.gesture);
btnSave = findViewById(R.id.btn_save);
btnCompare = findViewById(R.id.btn_compare);
editText = findViewById(R.id.edit_name);
gestureLibrary = GestureLibraries.fromFile("sdcard/gesture");
btnSave.setOnClickListener(this);
btnCompare.setOnClickListener(this);
gestureOverlayView.setGestureColor(R.color.teal_200);
gestureOverlayView.setGestureStrokeWidth(5);
gestureOverlayView.addOnGesturePerformedListener(new GestureOverlayView.OnGesturePerformedListener() {
@Override
public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
if (status == 1) {//保存手势
if (gesture == null || gesture.getLength() <= 0) return;
if (TextUtils.isEmpty(editText.getText().toString())) {
Toast.makeText(GestureActivity.this, "请输入手势名称", Toast.LENGTH_LONG).show();
return;
}
gestureLibrary.addGesture(editText.getText().toString(), gesture);
if (gestureLibrary.save()) {
Toast.makeText(GestureActivity.this, "保存手势成功", Toast.LENGTH_LONG).show();
}else{
Toast.makeText(GestureActivity.this, "保存手势失败", Toast.LENGTH_LONG).show();
}
} else if (status == 2) {//比较手势
ArrayList<Prediction> recognize = gestureLibrary.recognize(gesture);
Prediction prediction = recognize.get(0);
if (prediction.score >= 2) {
Toast.makeText(GestureActivity.this, prediction.name + "匹配成功", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(GestureActivity.this, prediction.name + "匹配失败", Toast.LENGTH_SHORT).show();
}
}
}
});
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_compare:
status = 2;
break;
case R.id.btn_save:
status = 1;
break;
}
}
}
