本文介绍了捏在Android中调整LinearLayout的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我需要缩放包含Image,TextViews等的整个布局.我发现缩放功能仅适用于Imageview.
I need to zoom the entire layout contains Image,TextViews etc.i found zoom functionalities only for Imageview.
推荐答案
创建自定义的 Layout
类,称为 ZoomeLinearLayout
.
Create a Custom Layout
Class Called ZoomeLinearLayout
.
ZoomLinearLayout.java
public class ZoomLinearLayout extends LinearLayout implements ScaleGestureDetector.OnScaleGestureListener {
private enum Mode {
NONE,
DRAG,
ZOOM
}
private static final float MIN_ZOOM = 1.0f;
private static final float MAX_ZOOM = 4.0f;
private Mode mode = Mode.NONE;
private float scale = 1.0f;
private float lastScaleFactor = 0f;
private float startX = 0f;
private float startY = 0f;
private float dx = 0f;
private float dy = 0f;
private float prevDx = 0f;
private float prevDy = 0f;
public ZoomLinearLayout(Context context) {
super(context);
init(context);
}
public ZoomLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public ZoomLinearLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
public void init(Context context) {
final ScaleGestureDetector scaleDetector = new ScaleGestureDetector(context, this);
this.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
if (scale > MIN_ZOOM) {
mode = Mode.DRAG;
startX = motionEvent.getX() - prevDx;
startY = motionEvent.getY() - prevDy;
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == Mode.DRAG) {
dx = motionEvent.getX() - startX;
dy = motionEvent.getY() - startY;
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
mode = Mode.ZOOM;
break;
case MotionEvent.ACTION_POINTER_UP:
mode = Mode.DRAG;
break;
case MotionEvent.ACTION_UP:
mode = Mode.NONE;
prevDx = dx;
prevDy = dy;
break;
}
scaleDetector.onTouchEvent(motionEvent);
if ((mode == Mode.DRAG && scale >= MIN_ZOOM) || mode == Mode.ZOOM) {
getParent().requestDisallowInterceptTouchEvent(true);
float maxDx = (child().getWidth() - (child().getWidth() / scale)) / 2 * scale;
float maxDy = (child().getHeight() - (child().getHeight() / scale)) / 2 * scale;
dx = Math.min(Math.max(dx, -maxDx), maxDx);
dy = Math.min(Math.max(dy, -maxDy), maxDy);
applyScaleAndTranslation();
}
return true;
}
});
}
@Override
public boolean onScaleBegin(ScaleGestureDetector scaleDetector) {
return true;
}
@Override
public boolean onScale(ScaleGestureDetector scaleDetector) {
float scaleFactor = scaleDetector.getScaleFactor();
if (lastScaleFactor == 0 || (Math.signum(scaleFactor) == Math.signum(lastScaleFactor))) {
scale *= scaleFactor;
scale = Math.max(MIN_ZOOM, Math.min(scale, MAX_ZOOM));
lastScaleFactor = scaleFactor;
} else {
lastScaleFactor = 0;
}
return true;
}
@Override
public void onScaleEnd(ScaleGestureDetector scaleDetector) {
}
private void applyScaleAndTranslation() {
child().setScaleX(scale);
child().setScaleY(scale);
child().setTranslationX(dx);
child().setTranslationY(dy);
}
private View child() {
return getChildAt(0);
}
}
然后在 Layout
文件中,用 ZoomLinearLayout
包裹要缩放的 LinearLayout
.请注意, ZoomLinearLayout
只有一个直接子级.
Then in Layout
file, Wrap your LinearLayout
which you want to zoom with ZoomLinearLayout
. Note that you have only one direct child for ZoomLinearLayout
.
<com.asif.test.ZoomLinearLayout
android:layout_width="match_parent"
android:id="@+id/zoom_linear_layout"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
</com.asif.test.ZoomLinearLayout>
现在在 Activity
中,创建 ZoomLinearLayout
对象,并为其设置 onTouch()
事件.
Now in Activity
, create ZoomLinearLayout
object and set the onTouch()
event for it.
final ZoomLinearLayout zoomLinearLayout = (ZoomLinearLayout) findViewById(R.id.zoom_linear_layout);
zoomLinearLayout.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
zoomLinearLayout.init(MainActivity.this);
return false;
}
});
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