位子|间隔时间_BannerViewAndroid只一个方向

篇首语：本文由编程笔记#小编为大家整理，主要介绍了BannerView Android 只一个方向相关的知识，希望对你有一定的参考价值。

居中 LAYOUT_MODE_CENTER

顶部 LAYOUT_MODE_TOP

底部 LAYOUT_MODE_BOTTOM

右往左布局 LAYOUT_RIGHT_TO_LEFT

BannerView

package com.example.bannerdemo;
import android.animation.Animator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.Interpolator;
public class BannerView extends ViewGroup implements Runnable
private final float SCALE_0 &＃61; 0.833333333333f;
private final float SCALE_1 &＃61; 0.916666667f;
private final float SCALE_2 &＃61; 1f;
private final float ALPHA_0 &＃61; 0.4f;
private final float ALPHA_1 &＃61; 0.8f;
private final float ALPHA_2 &＃61; 1.0f;
private final int DEFAULT_BASELINE &＃61; 30;
// index&＃61;0 child baseline
private int BASELINE_0 &＃61; 0;
// index&＃61;1 child baseline
private int BASELINE_1 &＃61; 0;
// index&＃61;2 child baseline
private int BASELINE_2 &＃61; 0;
//动画间隔时间
private int waitTime&＃61;1000;
// 只能向左滑动
private final int SCROLL_ORIENTATION_LEFT &＃61; 0;
// 只能向右滑动
private final int SCROLL_ORIENTATION_RIGHT &＃61; 1;
// 双向滑动
private final int SCROLL_ORIENTATION_ALL &＃61; 2;
private final int LAYOUT_MODE_TOP &＃61; 0;
private final int LAYOUT_MODE_CENTER &＃61; 1;
private final int LAYOUT_MODE_BOTTOM &＃61; 2;
private final int LAYOUT_LEFT_TO_RIGHT &＃61; 3;
private final int LAYOUT_RIGHT_TO_LEFT &＃61; 4;
// 布局模式
int layoutMode &＃61; LAYOUT_MODE_CENTER;
// 布局方向
int layoutOrientation &＃61; LAYOUT_LEFT_TO_RIGHT;
// 滑动方向
int scrollOrientation &＃61; SCROLL_ORIENTATION_LEFT;
// baseLine offset 子view偏移量
int baseLineOffset &＃61; DEFAULT_BASELINE;
// 最上面的左边距
int topLeftBaseLine &＃61; 0;
//item 点击事件
private OnItemClickListener onItemClickListener;
public BannerView(Context context)
this(context, null);

public BannerView(Context context, AttributeSet attrs)
this(context, attrs, 0);

public BannerView(Context context, AttributeSet attrs, int defStyleAttr)
super(context, attrs, defStyleAttr);
init();

private void init()

&＃64;Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
measureChildren(widthMeasureSpec, heightMeasureSpec);
setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));

&＃64;Override
protected void onLayout(boolean changed, int l, int t, int r, int b)
for (int i &＃61; 0; i < getChildCount(); i&＃43;&＃43;)
View child &＃61; getChildAt(i);
int baseLeftLine &＃61; getBaseLeftLine(child);
getBaseTopLine(i);
layoutChild(child, baseLeftLine);
if (i &＃61;&＃61; 2)
child.setOnClickListener(new OnClickListener()
&＃64;Override
public void onClick(View v)
if (onItemClickListener !&＃61; null)
LayoutParams lp &＃61; (LayoutParams) child.getLayoutParams();
onItemClickListener.onItemClick(lp.dataPosition);


);
else
child.setOnClickListener(null);



private int getBaseLeftLine(View child)
LayoutParams lp &＃61; (LayoutParams) child.getLayoutParams();
int baseLine &＃61; 0;
switch (lp.fromIndex)
case 0:
if (mOffsetPercent > 0)
baseLine &＃61; (int) (BASELINE_0 - mOffsetPercent * BASELINE_1);
if (baseLine < BASELINE_1)
baseLine &＃61; BASELINE_1;

lp.scale &＃61; (float) (SCALE_0 &＃43; ((SCALE_1 - SCALE_0) * mOffsetPercent));
if (lp.scale > SCALE_1)
lp.scale &＃61; SCALE_1;

else
baseLine &＃61; (int) (BASELINE_0 &＃43; mOffsetPercent * BASELINE_1);
if (baseLine < BASELINE_1)
baseLine &＃61; BASELINE_1;

lp.scale &＃61; (float) (SCALE_0 - ((SCALE_1 - SCALE_0) * mOffsetPercent));
if (lp.scale > SCALE_1)
lp.scale &＃61; SCALE_1;


break;
case 1:
// toIndex&＃61;2
if (mOffsetPercent > 0)
baseLine &＃61; (int) (BASELINE_1 - mOffsetPercent * BASELINE_1);
if (baseLine < BASELINE_2)
baseLine &＃61; BASELINE_2;

lp.scale &＃61; (float) (SCALE_1 &＃43; ((SCALE_2 - SCALE_1) * mOffsetPercent));
if (lp.scale > SCALE_2)
lp.scale &＃61; SCALE_2;

lp.alpha &＃61; (float) (ALPHA_1 &＃43; ((ALPHA_2 - ALPHA_1) * mOffsetPercent));
if (lp.alpha > ALPHA_2)
lp.alpha &＃61; ALPHA_2;

else
baseLine &＃61; (int) (BASELINE_1 &＃43; mOffsetPercent * BASELINE_1);
if (baseLine < BASELINE_2)
baseLine &＃61; BASELINE_2;

lp.scale &＃61; (float) (SCALE_1 - ((SCALE_2 - SCALE_1) * mOffsetPercent));
if (lp.scale > SCALE_2)
lp.scale &＃61; SCALE_2;

lp.alpha &＃61; (float) (ALPHA_1 - ((ALPHA_2 - ALPHA_1) * mOffsetPercent));
if (lp.alpha > ALPHA_2)
lp.alpha &＃61; ALPHA_2;


break;
case 2:
// toIndex&＃61; 0
if (mOffsetPercent > 0)
baseLine &＃61; (int) (BASELINE_2 &＃43; mOffsetPercent * BASELINE_0);
if (baseLine >&＃61; BASELINE_0)
baseLine &＃61; BASELINE_0;
else
baseLine &＃61; (int) (BASELINE_2 &＃43; mOffsetPercent * child.getWidth());

lp.scale &＃61; (float) (SCALE_2 - ((SCALE_2 - SCALE_0) * mOffsetPercent));
if (lp.scale <&＃61; SCALE_0)
lp.scale &＃61; SCALE_0;
else
lp.scale &＃61; SCALE_2;

lp.alpha &＃61; (float) (ALPHA_2 - ((ALPHA_2 - ALPHA_0) * mOffsetPercent));
if (lp.alpha >&＃61; ALPHA_0)
lp.alpha &＃61; ALPHA_0;
else
lp.alpha &＃61; ALPHA_2;

else
baseLine &＃61; (int) (BASELINE_2 &＃43; mOffsetPercent * BASELINE_0);
if (baseLine >&＃61; BASELINE_0)
baseLine &＃61; BASELINE_0;
else
baseLine &＃61; (int) (BASELINE_2 &＃43; mOffsetPercent * child.getWidth());

lp.scale &＃61; (float) (SCALE_2 &＃43; ((SCALE_2 - SCALE_0) * mOffsetPercent));
if (lp.scale <&＃61; SCALE_0)
lp.scale &＃61; SCALE_0;
else
lp.scale &＃61; SCALE_2;

lp.alpha &＃61; (float) (ALPHA_2 &＃43; ((ALPHA_2 - ALPHA_0) * mOffsetPercent));
if (lp.alpha <&＃61; ALPHA_0)
lp.alpha &＃61; ALPHA_0;
else
lp.alpha &＃61; ALPHA_2;


break;

return baseLine;

private int getBaseTopLine(int index)
int baseLine &＃61; 0;
switch (index)
case 0:
baseLine &＃61; 40;
break;
case 1:
baseLine &＃61; 20;
break;
case 2:
baseLine &＃61; 0;
break;

return baseLine;

private void layoutChild(View child, int baseLeftLine)
LayoutParams lp &＃61; (LayoutParams) child.getLayoutParams();
child.setAlpha(lp.alpha);
int childWidth &＃61; child.getMeasuredWidth();
int childHeight &＃61; (int) (child.getMeasuredHeight() * lp.scale);
int top &＃61; 0;
int bottom &＃61; 0;
if (layoutMode &＃61;&＃61; LAYOUT_MODE_CENTER)
top &＃61; (int) (getHeight() / 2.0f - childHeight / 2.0f);
bottom &＃61; (int) (getHeight() / 2.0f &＃43; childHeight / 2.0f);
else if (layoutMode &＃61;&＃61; LAYOUT_MODE_BOTTOM)
top &＃61; getHeight() - childHeight;
bottom &＃61; getHeight();
else if (layoutMode &＃61;&＃61; LAYOUT_MODE_TOP)
top &＃61; 0;
bottom &＃61; childHeight;

int left &＃61; 0;
int right &＃61; 0;
if (layoutOrientation &＃61;&＃61; LAYOUT_LEFT_TO_RIGHT)
left &＃61; baseLeftLine;
right &＃61; left &＃43; childWidth;
else if (layoutOrientation &＃61;&＃61; LAYOUT_RIGHT_TO_LEFT)
right &＃61; getWidth() - baseLeftLine;
left &＃61; right - childWidth;

child.layout(left &＃43; lp.leftMargin, top &＃43; lp.topMargin, right &＃43; lp.rightMargin, bottom &＃43; lp.bottomMargin);

private int measureWidth(int widthMeasureSpec)
int width &＃61; 0;
int mode &＃61; MeasureSpec.getMode(widthMeasureSpec);
int size &＃61; MeasureSpec.getSize(widthMeasureSpec);
if (mode &＃61;&＃61; MeasureSpec.EXACTLY)
width &＃61; size;
else
int maxChildWidth &＃61; 0;
for (int i &＃61; 0; i < getChildCount(); i&＃43;&＃43;)
View child &＃61; getChildAt(i);
LayoutParams layoutParams &＃61; (LayoutParams) child.getLayoutParams();
maxChildWidth &＃61; Math.max(maxChildWidth, child.getMeasuredWidth() &＃43; layoutParams.leftMargin &＃43; layoutParams.rightMargin);

width &＃61; maxChildWidth &＃43; 60;

return width;

private int measureHeight(int heightMeasureSpec)
int height &＃61; 0;
int mode &＃61; MeasureSpec.getMode(heightMeasureSpec);
int size &＃61; MeasureSpec.getSize(heightMeasureSpec);
if (mode &＃61;&＃61; MeasureSpec.EXACTLY)
height &＃61; size;
else
int maxChildHeight &＃61; 0;
for (int i &＃61; 0; i < getChildCount(); i&＃43;&＃43;)
View child &＃61; getChildAt(i);
LayoutParams layoutParams &＃61; (LayoutParams) child.getLayoutParams();
maxChildHeight &＃61; Math.max(maxChildHeight, child.getMeasuredHeight() &＃43; layoutParams.topMargin &＃43; layoutParams.bottomMargin);

height &＃61; maxChildHeight;

return height;

&＃64;Override
public void addView(View child, int index, ViewGroup.LayoutParams params)
if (index > 2)
return;

LayoutParams lp &＃61; params instanceof LayoutParams ? (LayoutParams) params : new LayoutParams(params);
lp.fromIndex &＃61; index;
switch (index)
case 0:
lp.scale &＃61; SCALE_0;
lp.alpha &＃61; ALPHA_0;
BASELINE_0 &＃61; baseLineOffset * 2;
break;
case 1:
lp.scale &＃61; SCALE_1;
lp.alpha &＃61; ALPHA_1;
BASELINE_1 &＃61; bas