reference
Android View visibility check: getLocalVisibleRect and getGlobalVisibleRect
getGlobalVisibleRect() and getLocalVisibleRect()
-
getGlobalVisibleRect()It is the coordinate position of the view's visible area相对于屏幕来说. -
getLocalVisibleRect()Is相对于自己坐标the position of the visible area of the view. -
Be sure to remember clearly
可见区域.
getGlobalVisibleRect(rect);
It uses the upper left corner of the screen as the reference system,
determines that part of the view is on the screen, and returns true (not blocked by the parent View).
On the other hand, if it is completely blocked by the parent View or itself is invisible, false is returned.
getLocalVisibleRect(rect);
- When the View is visible, the upper left corner of its own View is used as the reference system, and the origin of the coordinate system is the View's own coordinate origin.
- When the View is invisible, the upper left corner of the parent control is used as the reference system, and the origin of the coordinate system is the coordinate origin of the View's parent control.
DisplayUtil tool class:
import android.content.Context;
import android.graphics.Point;
import android.view.Display;
import android.view.WindowManager;
public class DisplayUtil {
/**
* 获取屏幕的实际高度
*/
public static int getScreenRealWidth(Context context) {
try {
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Point outSize = new Point();
display.getRealSize(outSize);
return outSize.x;
} catch (Throwable throwable) {
throwable.printStackTrace();
}
return 0;
}
/**
* 获取屏幕的实际高度
*/
public static int getScreenRealHeight(Context context) {
try {
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Point outSize = new Point();
display.getRealSize(outSize);
return outSize.y;
} catch (Throwable throwable) {
throwable.printStackTrace();
}
return 0;
}
/**
* 获取状态栏的高度
*
* @param context
* @return
*/
public static int getStatusBarHeight(Context context) {
int result = 0;
int resourceId = context.getResources()
.getIdentifier("status_bar_height", "dimen", "android");
if (resourceId > 0) {
result = context.getResources().getDimensionPixelSize(resourceId);
}
return result;
}
/**
* 获取导航栏的高度
*
* @param context
* @return
*/
public static int getNavBarHeight(Context context) {
int result = 0;
int resourceId = context.getResources()
.getIdentifier("navigation_bar_height", "dimen", "android");
if (resourceId > 0) {
result = context.getResources().getDimensionPixelSize(resourceId);
}
return result;
}
}
test2.xml :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/holo_blue_light">
<TextView
android:id="@+id/tv"
android:layout_width="300dp"
android:layout_height="150dp"
android:background="@android:color/holo_orange_light"
android:text=""
android:textColor="@android:color/black" />
<View
android:layout_width="match_parent"
android:layout_height="56dp"
android:background="@android:color/holo_red_dark" />
<View
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_alignParentBottom="true"
android:background="@android:color/holo_green_dark" />
</RelativeLayout>
TestActivity.java :
import android.annotation.SuppressLint;
import android.graphics.Point;
import android.graphics.Rect;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.TextView;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
public class TestActivity extends AppCompatActivity {
private static final String TAG = TestActivity.class.getSimpleName();
private TextView mTv;
private RelativeLayout mRoot;
private int lastX = 0;
private int lastY = 0;
@Override
@SuppressLint("ClickableViewAccessibility")
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test2);
mRoot = findViewById(R.id.root);
mTv = findViewById(R.id.tv);
// 屏幕尺寸 : 1920*990，三个均包含状态栏高度，不包含导航栏高度
{
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
Log.e(TAG, "1 width = " + dm.widthPixels
+ ", height = " + dm.heightPixels);
//获取Android屏幕尺寸
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
Log.e(TAG, "2 width = " + size.x
+ ", height = " + size.y);
DisplayMetrics metrics = getResources().getDisplayMetrics();
Log.e(TAG, "3 width = " + metrics.widthPixels
+ ", height = " + metrics.heightPixels);
}
// 屏幕尺寸 : 1920*1080，三个均包含状态栏高度 + 导航栏高度
{
mRoot.post(new Runnable() {
@Override
public void run() {
Log.e(TAG, "decorView "
+ "width = " + getWindow().getDecorView().getWidth()//1920
+ ",height = " + getWindow().getDecorView().getHeight()//1080
+ " ; root "
+ "width = " + mRoot.getWidth()//1920
+ ",height = " + mRoot.getHeight());//1080
}
});
int height = DisplayUtil.getScreenRealHeight(this);
Log.e(TAG, "height = " + height);//1080
int width = DisplayUtil.getScreenRealWidth(this);
Log.e(TAG, "width = " + width);//1920
}
// 状态栏=84 ， 导航栏=90
{
int statusBarHeight = DisplayUtil.getStatusBarHeight(this);
Log.e(TAG, "statusBarHeight = " + statusBarHeight);
int navigationBarHeight = DisplayUtil.getNavBarHeight(this);
Log.e(TAG, "navigationBarHeight = " + navigationBarHeight);
}
mTv.setOnTouchListener(new View.OnTouchListener() {
@SuppressLint("SetTextI18n")
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
lastX = (int) event.getRawX();
lastY = (int) event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
int dx = (int) event.getRawX() - lastX;
int dy = (int) event.getRawY() - lastY;
int left = v.getLeft() + dx;
int top = v.getTop() + dy;
int right = v.getRight() + dx;
int bottom = v.getBottom() + dy;
v.layout(left, top, right, bottom);
lastX = (int) event.getRawX();
lastY = (int) event.getRawY();
//getLocalVisibleRect的作用是获取视图本身可见的坐标区域，
// 坐标以自己的左上角为原点（0，0）
//只要该视图没有被遮挡，targetView.getLocalVisibleRect()的坐标总是等于:
//(0, 0, targetView.getwidth(), targetView.getHeight())
Rect localRect = new Rect();
v.getLocalVisibleRect(localRect);
//getGlobalVisibleRect方法的作用是获取视图在屏幕坐标中的可视区域
Rect globalRect = new Rect();
//globalOffset的值就是targetView原点偏离屏幕坐标原点的距离。
Point globalOffset = new Point();
v.getGlobalVisibleRect(globalRect, globalOffset);
Rect rect = new Rect();
mTv.getWindowVisibleDisplayFrame(rect);
mTv.setText("local = " + localRect.toString()
+ "\n" + "global = " + globalRect.toString()
+ "\n" + "globalOffset = " + globalOffset.x + "," + globalOffset.y
+ "\n" + "statusBar top = " + rect.top
+ "\n" + "navigationBar top = " + (rect.bottom)
);
break;
case MotionEvent.ACTION_UP:
break;
}
return true;
}
});
}
}