捏缩放和平移 [英] Pinch Zoom and Pan
问题描述
我有LinearLayout中为主要布局的活动。在该布局，有一个按钮，增加了一个视图（R.layout.motor_block）到主要布局（R.id.layout）：
I have an activity with LinearLayout as its main Layout. In that layout, there is a button that adds a View (R.layout.motor_block) to the main layout (R.id.layout):
LayoutInflater inflater =
(LayoutInflater)this.getSystemService( Context.LAYOUT_INFLATER_SERVICE );
View iv = inflater.inflate( R.layout.motor_block, null );
RelativeLayout rl = (RelativeLayout) findViewById(R.id.layout);
rl.addView(iv);
这工作得很好，但是当我添加更多的意见，画面被充满了他们，所以我需要的方式加入泛这样我就可以通过所有的意见，扩展的大小。 我也想补充变焦。
This works fine, but when I add more Views, the screen gets filled up with them so I need a way to "extend" the size by adding pan so I can go through all the views. I also want to add zoom.
我试图用一个web视图：
I tried to use a WebView:
RelativeLayout rl = (RelativeLayout) findViewById(R.id.layout);
WebView wv = (WebView) findViewById(R.id.webView1);
wv.getSettings().setSupportZoom(true);
wv.getSettings().setBuiltInZoomControls(true);
wv.getSettings().setUseWideViewPort(true);
wv.getSettings().setLoadWithOverviewMode(true);
wv.getSettings().setDisplayZoomControls(false);
wv.getSettings().setDefaultZoom(WebSettings.ZoomDensity.FAR);
wv.addView(iv);
的意见被添加到它，和平移工程。问题是，当我放大，web视图缩放背景，视图不会改变大小。
The Views get added to it, and pan works. The problem is that when I zoom, the webView zooms the background, and the Views don't change size.
我也尝试了一些自定义的意见，但他们不支持的意见与孩子的意见。
I also tried some custom views but they didn't support views with child views.
什么是实现这一目标的最佳方式是什么？
What is the best way to accomplish this?
推荐答案
只是一个例子。使用setTranslationX / Y和setScaleX / Y主容器视图。其子将规模并翻译它。
Just an example. Use setTranslationX/Y and setScaleX/Y on the main container view. Its children will scale and translate with it.
public class MainActivity extends Activity {
private RelativeLayout mainLayout;
private ScaleGestureDetector scaleGestureDetector;
private float scale = 1;
private PointF touchPoint;
private PointF pan;
private boolean isScaling;
private boolean endScalingNextUp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mainLayout = (RelativeLayout) findViewById(id.main_layout);
scaleGestureDetector = new ScaleGestureDetector(this, new ExampleScaleGestureListener());
Button b = ((Button) findViewById(id.btn_reset));
b.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
reset();
}
});
reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
scaleGestureDetector.onTouchEvent(event);
if (scale != 1 && !isScaling) {
float x = event.getRawX();
float y = event.getRawY();
if (event.getAction() == MotionEvent.ACTION_DOWN) {
touchPoint = new PointF(x, y);
} else if (event.getAction() == MotionEvent.ACTION_MOVE && touchPoint != null) {
pan.x = x - touchPoint.x;
pan.y = y - touchPoint.y;
panView();
}
}
if (isScaling && endScalingNextUp) {
if (event.getAction() == MotionEvent.ACTION_POINTER_UP) {
endScalingNextUp = false;
isScaling = false;
}
}
return true;
}
private void setPivot(float focusX, float focusY) {
mainLayout.setPivotX(focusX);
mainLayout.setPivotY(focusY);
}
private void scaleView() {
mainLayout.setScaleX(scale);
mainLayout.setScaleY(scale);
}
private void panView() {
mainLayout.setTranslationX(pan.x);
mainLayout.setTranslationY(pan.y);
}
private void reset() {
setPivot(0, 0);
scale = 1;
scaleView();
pan = new PointF(0, 0);
panView();
isScaling = false;
}
private class ExampleScaleGestureListener implements OnScaleGestureListener {
private static final float SCALE_SPEED = .02f;
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
endScalingNextUp = true;
}
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
float focusX = detector.getFocusX();
float focusY = detector.getFocusY();
setPivot(focusX, focusY);
isScaling = true;
endScalingNextUp = false;
return true;
}
@Override
public boolean onScale(ScaleGestureDetector detector) {
isScaling = true;
endScalingNextUp = false;
if (detector.getScaleFactor() < 1) {
scale -= SCALE_SPEED;
} else if (detector.getScaleFactor() > 1) {
scale += SCALE_SPEED;
}
scaleView();
return true;
}
}
}
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:id="@+id/main_layout"
tools:context=".MainActivity" >
<TextView
android:id="@+id/tv"
android:layout_centerInParent="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/tv"
android:layout_marginBottom="69dp"
android:layout_marginRight="29dp"
android:layout_toLeftOf="@+id/tv"
android:src="@drawable/ic_launcher" />
<Button
android:id="@+id/btn_reset"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/tv"
android:layout_centerHorizontal="true"
android:layout_marginTop="22dp"
android:text="Reset" />
</RelativeLayout>
这篇关于捏缩放和平移的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
