Android 具有動畫的 Viewpager滑動CircleIndicator指示器
阿新 • • 發佈:2019-02-14
1.自定義屬性:attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="CircleIndicator">
<attr name="ci_radius" format="dimension" />
<attr name="ci_margin" format="dimension" />
<attr name="ci_background" format="color|integer" />
<attr name="ci_selected_background" format="color|integer" />
<attr name="ci_gravity">
<enum name="left" value="0" />
<enum name="center" value="1" />
<enum name="right" value="2" />
</attr>
<attr name="ci_mode">
<enum name="inside" value="0" />
<enum name="outside" value="1" />
<enum name="solo" value="2" />
</attr>
</declare-styleable>
</resources>
2.自定義控制元件
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
public class CircleIndicator extends View {
private ViewPager viewPager;
private List<ShapeHolder> tabItems;
private ShapeHolder movingItem;
//config list
private int mCurItemPosition;
private float mCurItemPositionOffset;
private float mIndicatorRadius;
private float mIndicatorMargin;
private int mIndicatorBackground;
private int mIndicatorSelectedBackground;
private Gravity mIndicatorLayoutGravity;
private Mode mIndicatorMode;
//default value
private final int DEFAULT_INDICATOR_RADIUS = 10;
private final int DEFAULT_INDICATOR_MARGIN = 40;
private final int DEFAULT_INDICATOR_BACKGROUND = Color.BLUE;
private final int DEFAULT_INDICATOR_SELECTED_BACKGROUND = Color.RED;
private final int DEFAULT_INDICATOR_LAYOUT_GRAVITY = Gravity.CENTER.ordinal();
private final int DEFAULT_INDICATOR_MODE = Mode.SOLO.ordinal();
public enum Gravity{
LEFT,
CENTER,
RIGHT
}
public enum Mode{
INSIDE,
OUTSIDE,
SOLO
}
public CircleIndicator(Context context) {
super(context);
init(context, null);
}
public CircleIndicator(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs);
}
public CircleIndicator(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs);
}
private void init(Context context,AttributeSet attrs){
tabItems = new ArrayList<>();
handleTypedArray(context, attrs);
}
private void handleTypedArray(Context context, AttributeSet attrs) {
if(attrs == null)
return;
TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CircleIndicator);
mIndicatorRadius = typedArray.getDimensionPixelSize(R.styleable.CircleIndicator_ci_radius, DEFAULT_INDICATOR_RADIUS);
mIndicatorMargin = typedArray.getDimensionPixelSize(R.styleable.CircleIndicator_ci_margin, DEFAULT_INDICATOR_MARGIN);
mIndicatorBackground = typedArray.getColor(R.styleable.CircleIndicator_ci_background, DEFAULT_INDICATOR_BACKGROUND);
mIndicatorSelectedBackground = typedArray.getColor(R.styleable.CircleIndicator_ci_selected_background,DEFAULT_INDICATOR_SELECTED_BACKGROUND);
int gravity = typedArray.getInt(R.styleable.CircleIndicator_ci_gravity,DEFAULT_INDICATOR_LAYOUT_GRAVITY);
mIndicatorLayoutGravity = Gravity.values()[gravity];
int mode = typedArray.getInt(R.styleable.CircleIndicator_ci_mode,DEFAULT_INDICATOR_MODE);
mIndicatorMode = Mode.values()[mode];
typedArray.recycle();
}
public void setViewPager(final ViewPager viewPager){
this.viewPager = viewPager;
createTabItems();
createMovingItem();
setUpListener();
}
private void setUpListener() {
viewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
super.onPageScrolled(position, positionOffset, positionOffsetPixels);
if(mIndicatorMode != Mode.SOLO){
trigger(position,positionOffset);
}
}
@Override
public void onPageSelected(int position) {
super.onPageSelected(position);
if(mIndicatorMode == Mode.SOLO){
trigger(position,0);
}
}
});
}
/**
* trigger to redraw the indicator when the ViewPager's selected item changed!
* @param position
* @param positionOffset
*/
private void trigger(int position,float positionOffset){
CircleIndicator.this.mCurItemPosition = position;
CircleIndicator.this.mCurItemPositionOffset = positionOffset;
Log.e("CircleIndicator", "onPageScrolled()" + position + ":" + positionOffset);
requestLayout();
invalidate();
}
private void createTabItems() {
for (int i = 0; i < viewPager.getAdapter().getCount(); i++) {
OvalShape circle = new OvalShape();
ShapeDrawable drawable = new ShapeDrawable(circle);
ShapeHolder shapeHolder = new ShapeHolder(drawable);
Paint paint = drawable.getPaint();
paint.setColor(mIndicatorBackground);
paint.setAntiAlias(true);
shapeHolder.setPaint(paint);
tabItems.add(shapeHolder);
}
}
private void createMovingItem() {
OvalShape circle = new OvalShape();
ShapeDrawable drawable = new ShapeDrawable(circle);
movingItem = new ShapeHolder(drawable);
Paint paint = drawable.getPaint();
paint.setColor(mIndicatorSelectedBackground);
paint.setAntiAlias(true);
switch (mIndicatorMode){
case INSIDE:
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_ATOP));
break;
case OUTSIDE:
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OVER));
break;
case SOLO:
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
break;
}
movingItem.setPaint(paint);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
Log.e("CircleIndicator","onLayout()");
super.onLayout(changed, left, top, right, bottom);
final int width = getWidth();
final int height = getHeight();
layoutTabItems(width, height);
layoutMovingItem(mCurItemPosition, mCurItemPositionOffset);
}
private void layoutTabItems(final int containerWidth,final int containerHeight){
if(tabItems == null){
throw new IllegalStateException("forget to create tabItems?");
}
final float yCoordinate = containerHeight*0.5f;
final float startPosition = startDrawPosition(containerWidth);
for(int i=0;i<tabItems.size();i++){
ShapeHolder item = tabItems.get(i);
item.resizeShape(2* mIndicatorRadius,2* mIndicatorRadius);
item.setY(yCoordinate- mIndicatorRadius);
float x = startPosition + (mIndicatorMargin + mIndicatorRadius*2)*i;
item.setX(x);
}
}
private float startDrawPosition(final int containerWidth){
if(mIndicatorLayoutGravity == Gravity.LEFT)
return 0;
float tabItemsLength = tabItems.size()*(2* mIndicatorRadius + mIndicatorMargin)- mIndicatorMargin;
if(containerWidth<tabItemsLength){
return 0;
}
if(mIndicatorLayoutGravity == Gravity.CENTER){
return (containerWidth-tabItemsLength)/2;
}
return containerWidth - tabItemsLength;
}
private void layoutMovingItem(final int position,final float positionOffset){
if(movingItem == null){
throw new IllegalStateException("forget to create movingItem?");
}
if(tabItems.size() == 0) {
return;
}
ShapeHolder item = tabItems.get(position);
movingItem.resizeShape(item.getWidth(), item.getHeight());
float x = item.getX()+(mIndicatorMargin + mIndicatorRadius*2)*positionOffset;
movingItem.setX(x);
movingItem.setY(item.getY());
}
@Override
protected void onDraw(Canvas canvas) {
Log.e("CircleIndicator", "onDraw()");
super.onDraw(canvas);
int sc = canvas.saveLayer(0, 0, getWidth(), getHeight(), null,
Canvas.MATRIX_SAVE_FLAG |
Canvas.CLIP_SAVE_FLAG |
Canvas.HAS_ALPHA_LAYER_SAVE_FLAG |
Canvas.FULL_COLOR_LAYER_SAVE_FLAG |
Canvas.CLIP_TO_LAYER_SAVE_FLAG);
for(ShapeHolder item : tabItems){
drawItem(canvas,item);
}
if(movingItem != null){
drawItem(canvas,movingItem);
}
canvas.restoreToCount(sc);
}
private void drawItem(Canvas canvas,ShapeHolder shapeHolder )
{
canvas.save();
canvas.translate(shapeHolder.getX(),shapeHolder.getY());
shapeHolder.getShape().draw(canvas);
canvas.restore();
}
public void setIndicatorRadius(float mIndicatorRadius) {
this.mIndicatorRadius = mIndicatorRadius;
}
public void setIndicatorMargin(float mIndicatorMargin) {
this.mIndicatorMargin = mIndicatorMargin;
}
public void setIndicatorBackground(int mIndicatorBackground) {
this.mIndicatorBackground = mIndicatorBackground;
}
public void setIndicatorSelectedBackground(int mIndicatorSelectedBackground) {
this.mIndicatorSelectedBackground = mIndicatorSelectedBackground;
}
public void setIndicatorLayoutGravity(Gravity mIndicatorLayoutGravity) {
this.mIndicatorLayoutGravity = mIndicatorLayoutGravity;
}
public void setIndicatorMode(Mode mIndicatorMode) {
this.mIndicatorMode = mIndicatorMode;
}
}
3.顯示圓的動畫效果
import android.graphics.Paint;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.Shape;
public class ShapeHolder {
private float x = 0, y = 0;//圓的x、y座標
private ShapeDrawable shape;
private int color;
private float alpha = 1f;
private Paint paint;
public void setPaint(Paint value) {
paint = value;
}
public Paint getPaint() {
return paint;
}
public void setX(float value) {
x = value;
}
public float getX() {
return x;
}
public void setY(float value) {
y = value;
}
public float getY() {
return y;
}
public void setShape(ShapeDrawable value) {
shape = value;
}
public ShapeDrawable getShape() {
return shape;
}
public int getColor() {
return color;
}
public void setColor(int value) {
shape.getPaint().setColor(value);
color = value;
}
public void setAlpha(float alpha) {
this.alpha = alpha;
shape.setAlpha((int) ((alpha * 255f) + .5f));
}
public float getWidth() {
return shape.getShape().getWidth();
}
public void setWidth(float width) {
Shape s = shape.getShape();
s.resize(width, s.getHeight());
}
public float getHeight() {
return shape.getShape().getHeight();
}
public void setHeight(float height) {
Shape s = shape.getShape();
s.resize(s.getWidth(), height);
}
public void resizeShape(final float width,final float height){
shape.getShape().resize(width,height);
}
public ShapeHolder(ShapeDrawable s) {
shape = s;
}
}
4.main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:CircleIndicator="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center" >
</android.support.v4.view.ViewPager>
<com.example.circleindicator_master.CircleIndicator
android:id="@+id/indicator"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
CircleIndicator:ci_background="@android:color/white"
CircleIndicator:ci_gravity="center"
CircleIndicator:ci_margin="5dp"
CircleIndicator:ci_mode="outside"
CircleIndicator:ci_radius="10dp"
CircleIndicator:ci_selected_background="0xffe6454a" />
</RelativeLayout>
5.Maintivity
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
public class MainActivity extends Activity {
private List<View> viewList;
private ViewPager viewPager;
private CircleIndicator circleIndicator;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initData();
viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(pagerAdapter);
circleIndicator = (CircleIndicator) findViewById(R.id.indicator);
circleIndicator.setViewPager(viewPager);
}
private void initData(){
viewList = new ArrayList<View>();
Random random = new Random();
for(int i=0;i<5;i++){
View view = new View(this);
view.setBackgroundColor(0xff000000| random.nextInt(0x00ffffff));
viewList.add(view);
}
}
PagerAdapter pagerAdapter = new PagerAdapter() {
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override
public int getCount() {
return viewList.size();
}
@Override
public void destroyItem(ViewGroup container, int position,
Object object) {
container.removeView(viewList.get(position));
}
@Override
public int getItemPosition(Object object) {
return super.getItemPosition(object);
}
@Override
public CharSequence getPageTitle(int position) {
return "title";
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
container.addView(viewList.get(position));
return viewList.get(position);
}
};
}
//說明:在使用PagerAdapter時候,跟List<Vew>集合完美結合封裝起來,這裡不做封裝了,很簡單的。
效果圖: