放大和缩小，仅滚动或抛帧布局

Question

我将实现姿势检测器。我到处都是。我有这样的布局：

<?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"
android:background="@drawable/sfondo_old"
tools:context=".activities.Board1">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:focusableInTouchMode="true">
<include
android:id="@+id/toolbar"
layout="@layout/toolbar_menu_disegno"
android:visibility="gone" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/toolbar"
android:orientation="vertical"
android:weightSum="2">

<FrameLayout
android:id="@+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1.99"> -->

<!-- IMAGE LOADED -->
<ImageView
android:id="@+id/area_campo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/campo1"
/>
<!-- CUSTOM DRAWING VIEW -->
<it.colan.matchup.ui.component.DrawingView
android:id="@+id/area_disegno"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>

<!-- </FrameLayout> -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/area_disegno"
android:layout_weight="0.01"
android:orientation="horizontal"
android:weightSum="1">
<include
android:id="@+id/strumenti"
layout="@layout/menu_strumenti"
android:layout_alignParentLeft="true"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal"
android:gravity="center"
android:background="@color/black"
/>

</LinearLayout>
</LinearLayout>
</RelativeLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

我试着在这里应用手势检测器，但当我尝试用手势缩放时，如果我触摸外部框架布局，它会起作用，但当缩放内部框架布局时不起作用。为什么？

这是我的Board1活动代码(删除按钮点击监听器和其他(：

public class Board1 extends AppCompatActivity {

private DrawingView areaDisegno; // for drawing
private ImageView areaCampo; // image behind drawing

private FrameLayout frameLayout; // all entire layout which can zoom and scroll for moving around 

private int mCurrentBackgroundColor;
private int mCurrentColor;
private int mCurrentStroke;
private static final int MAX_STROKE_WIDTH = 50;

private ScaleGestureDetector mScaleGestureDetector;
private GestureDetector mGestureDetector;
private float mScaleFactor = 1.0f;
public boolean onTouchEvent(MotionEvent motionEvent) {
mScaleGestureDetector.onTouchEvent(motionEvent);
mGestureDetector.onTouchEvent(motionEvent);
return true;
}
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
return super.onScroll(e1, e2, distanceX, distanceY);
}

}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector scaleGestureDetector){
if(!zoomBloccato) {
mScaleFactor *= scaleGestureDetector.getScaleFactor();
Log.d("DEBUG", "Board 1 - Scalefactor " + mScaleFactor);
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
frameLayout.setScaleX(mScaleFactor);
frameLayout.setScaleY(mScaleFactor);
}
return true;
}

}
@Override
protected void onCreate(Bundle savedInstanceState) {
supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
getWindow().setNavigationBarColor(getResources().getColor(R.color.black));
}
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_board1);
mScaleGestureDetector = new ScaleGestureDetector(this, new ScaleListener());
mGestureDetector = new GestureDetector(this, new GestureListener());
ActivityCompat.requestPermissions(Board1.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
EXTERNAL_STORAGE_PERMISSION_CODE);

areaDisegno = findViewById(R.id.area_disegno);
areaCampo = findViewById(R.id.area_campo);
frameLayout = findViewById(R.id.frameLayout);

inizializzaAreaDisegno();
mCurrentColor = Color.BLACK;
areaDisegno.setPaintColor(mCurrentColor);

mCurrentStroke = 30;
areaDisegno.setPaintStrokeWidth(mCurrentStroke);
areaDisegno.setDisegnoAbilitato(true);

}

private void inizializzaAreaDisegno()
{
//   mCurrentBackgroundColor = ContextCompat.getColor(this, android.R.color.white);
mCurrentColor = ContextCompat.getColor(this, android.R.color.black);
mCurrentStroke = 10;
areaDisegno.setBackgroundColor(mCurrentBackgroundColor);
areaDisegno.setBackgroundColor(mCurrentColor);
areaDisegno.setPaintStrokeWidth(mCurrentStroke);
}

}

我只尝试过框架布局，但没有成功。放大时我只能放大、缩小和滚动，但不能工作：(。谢谢Cris

Answer 1

您可以使用以下代码通过滚动放大、缩小

private float mScale = 1f;
private ScaleGestureDetector mScaleDetector;
GestureDetector gestureDetector;
//step 2: create instance from GestureDetector(this step sholude be place into onCreate())
gestureDetector = new GestureDetector(this, new GestureListener());
// animation for scalling
mScaleDetector = new ScaleGestureDetector(this, new ScaleGestureDetector.SimpleOnScaleGestureListener() 
{                                   
@Override
public boolean onScale(ScaleGestureDetector detector) 
{
float scale = 1 - detector.getScaleFactor();
float prevScale = mScale;
mScale += scale;
if (mScale < 0.1f) // Minimum scale condition:
mScale = 0.1f;
if (mScale > 10f) // Maximum scale condition:
mScale = 10f;
ScaleAnimation scaleAnimation = new ScaleAnimation(1f / prevScale, 1f / mScale, 1f / prevScale, 1f / mScale, detector.getFocusX(), detector.getFocusY());
scaleAnimation.setDuration(0);
scaleAnimation.setFillAfter(true);
ScrollView layout =(ScrollView) findViewById(R.id.scrollViewZoom);
layout.startAnimation(scaleAnimation);
return true;
}
});

// step 3: override dispatchTouchEvent()
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
super.dispatchTouchEvent(event);
mScaleDetector.onTouchEvent(event);
gestureDetector.onTouchEvent(event);
return gestureDetector.onTouchEvent(event);
}
//step 4: add private class GestureListener
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onDown(MotionEvent e) {
return true;
}
// event when double tap occurs
@Override
public boolean onDoubleTap(MotionEvent e) {
// double tap fired.
return true;
}
}