Android 圆形手表ListView圆弧滚动
智能手表发展迅速,很多开发的兄弟姐妹们都用过,分享一下圆盘手表的圆弧滚动ListView源代码,先上原理图:圆圈指的圆形屏幕的每个应用所处的位置,让个每个ListView的Item沿圆形表盘滚动,其实就是数学公式,圆上任一点计算公式。通过计算圆上任一点的X坐标,计算出Item需要向右平移的距离,从而实现ListView的每一个Item沿圆盘表盘边缘滚动。
JAVA代码:自定义ListView的Item布局控件
package video.xforms.www.util;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.WindowManager;
import android.widget.LinearLayout;
import video.xforms.www.AppContext;
/**
* @Created by 2022/12/26.
* @author 尹雪峰
*/
public class ListViewRound extends LinearLayout {
private int h = 0;
public ListViewRound(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void setParentHeight(int height) {
h = height;
}
@Override
protected void dispatchDraw(Canvas canvas) {
canvas.save();
int top = getTop();
float trans = onTranslate(top, h);
Matrix m = canvas.getMatrix();
//m.preTranslate(getWidth() / 8, 0);
m.postTranslate(trans , 0);
canvas.concat(m);
super.dispatchDraw(canvas);
canvas.restore();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
//重点:计算Item 偏移量的函数
private float onTranslate(int top,int h){
float result = 0f;
//检查屏幕是否是圆的
if(!AppContext.getIsRound()){
//(可以注释这个判断)
int radius = getScreenWidth() / 2 - 62; //屏幕的半径 - Item上需要向左平移的部分
if(top <= h/2f){
//左边半圆的上半部分
result = (float) Math.abs(radius - Math.sqrt( Math.pow(radius, 2) - Math.pow(radius - top, 2)));
}else if(top > h/2f){
//左边半圆的下半部分
result = (float) Math.abs(radius - Math.sqrt( Math.pow(radius, 2) - Math.pow(top - radius, 2)) );
}
}
return result;
}
private int getScreenWidth() {
WindowManager manager = (WindowManager) AppContext.getContext().getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics dm = new DisplayMetrics();
manager.getDefaultDisplay().getMetrics(dm);
return dm.widthPixels;
}
}
XML(ListView的Item XML样式)
<?xml version="1.0" encoding="utf-8"?>
<video.xforms.www.util.ListViewRound
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/video_views"
android:orientation="horizontal"
android:layout_width="match_parent"
android:padding="12dp"
android:layout_height="match_parent">
<ImageView
android:id="@+id/video_img"
android:background="@drawable/i1"
android:layout_width="80dp"
android:layout_height="80dp" />
<LinearLayout
android:paddingLeft="12dp"
android:orientation="vertical"
android:layout_gravity="center_vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/video_name"
android:textSize="26dp"
android:ellipsize="end"
android:singleLine="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/video_size"
android:textSize="22dp"
android:layout_marginTop="6dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
</video.xforms.www.util.ListViewRound>