48、ViewFlow ---- 滑动广告页

package org.taptwo.android.widget;

import com.viewflowtest.cjy.R;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.os.AsyncTask;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.Animation.AnimationListener;

public class CircleFlowIndicator extends View implements FlowIndicator,
AnimationListener {
private static final int STYLE_STROKE = 0;
private static final int STYLE_FILL = 1;

private float radius = 4;
private float circleSeparation = 2*radius+radius;
private float activeRadius = 0.5f;
private int fadeOutTime = 0;
private final Paint mPaintInactive = new Paint(Paint.ANTI_ALIAS_FLAG);
private final Paint mPaintActive = new Paint(Paint.ANTI_ALIAS_FLAG);
private ViewFlow viewFlow;
private int currentScroll = 0;
private int flowWidth = 0;
private FadeTimer timer;
public AnimationListener animationListener = this;
private Animation animation;
private boolean mCentered = false;

/**
* Default constructor
*
* @param context
*/
public CircleFlowIndicator(Context context) {
super(context);
initColors(0xFFFFFFFF, 0xFFFFFFFF, STYLE_FILL, STYLE_STROKE);
}

/**
* The contructor used with an inflater
*
* @param context
* @param attrs
*/
public CircleFlowIndicator(Context context, AttributeSet attrs) {
super(context, attrs);
// Retrieve styles attributs
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.CircleFlowIndicator);

// Gets the inactive circle type, defaulting to "fill"
int activeType = a.getInt(R.styleable.CircleFlowIndicator_activeType,
STYLE_FILL);

int activeDefaultColor = 0xFFFFFFFF;

// Get a custom inactive color if there is one
int activeColor = a
.getColor(R.styleable.CircleFlowIndicator_activeColor,
activeDefaultColor);

// Gets the inactive circle type, defaulting to "stroke"
int inactiveType = a.getInt(
R.styleable.CircleFlowIndicator_inactiveType, STYLE_STROKE);

int inactiveDefaultColor = 0x44FFFFFF;
// Get a custom inactive color if there is one
int inactiveColor = a.getColor(
R.styleable.CircleFlowIndicator_inactiveColor,
inactiveDefaultColor);

// Retrieve the radius
radius = a.getDimension(R.styleable.CircleFlowIndicator_radius, 4.0f);

circleSeparation = a.getDimension(R.styleable.CircleFlowIndicator_circleSeparation, 2*radius+radius);
activeRadius = a.getDimension(R.styleable.CircleFlowIndicator_activeRadius, 0.5f);
// Retrieve the fade out time
fadeOutTime = a.getInt(R.styleable.CircleFlowIndicator_fadeOut, 0);

mCentered = a.getBoolean(R.styleable.CircleFlowIndicator_centered, false);

initColors(activeColor, inactiveColor, activeType, inactiveType);
}

private void initColors(int activeColor, int inactiveColor, int activeType,
int inactiveType) {
// Select the paint type given the type attr
switch (inactiveType) {
case STYLE_FILL:
mPaintInactive.setStyle(Style.FILL);
break;
default:
mPaintInactive.setStyle(Style.STROKE);
}
mPaintInactive.setColor(inactiveColor);

// Select the paint type given the type attr
switch (activeType) {
case STYLE_STROKE:
mPaintActive.setStyle(Style.STROKE);
break;
default:
mPaintActive.setStyle(Style.FILL);
}
mPaintActive.setColor(activeColor);
}

/*
* (non-Javadoc)
*
* @see android.view.View#onDraw(android.graphics.Canvas)
*/
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int count = 3;
if (viewFlow != null) {
count = viewFlow.getViewsCount();
}

//this is the amount the first circle should be offset to make the entire thing centered
float centeringOffset = 0;

int leftPadding = getPaddingLeft();

// Draw stroked circles
for (int iLoop = 0; iLoop < count; iLoop++) {
canvas.drawCircle(leftPadding + radius
+ (iLoop * circleSeparation) + centeringOffset,
getPaddingTop() + radius, radius, mPaintInactive);
}
float cx = 0;
if (flowWidth != 0) {
// Draw the filled circle according to the current scroll
cx = (currentScroll * circleSeparation) / flowWidth;
}
// The flow width has been upadated yet. Draw the default position
canvas.drawCircle(leftPadding + radius + cx+centeringOffset, getPaddingTop()
+ radius, radius + activeRadius, mPaintActive);
}

/*
* (non-Javadoc)
*
* @see
* org.taptwo.android.widget.ViewFlow.ViewSwitchListener#onSwitched(android
* .view.View, int)
*/
@Override
public void onSwitched(View view, int position) {
}

/*
* (non-Javadoc)
*
* @see
* org.taptwo.android.widget.FlowIndicator#setViewFlow(org.taptwo.android
* .widget.ViewFlow)
*/
@Override
public void setViewFlow(ViewFlow view) {
resetTimer();
viewFlow = view;
flowWidth = viewFlow.getWidth();
invalidate();
}

/*
* (non-Javadoc)
*
* @see org.taptwo.android.widget.FlowIndicator#onScrolled(int, int, int,
* int)
*/
@Override
public void onScrolled(int h, int v, int oldh, int oldv) {
setVisibility(View.VISIBLE);
resetTimer();
flowWidth = viewFlow.getWidth();
if(viewFlow.getViewsCount()*flowWidth!=0){
currentScroll = h%(viewFlow.getViewsCount()*flowWidth);
}else {
currentScroll = h;
}
invalidate();
}

/*
* (non-Javadoc)
*
* @see android.view.View#onMeasure(int, int)
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(measureWidth(widthMeasureSpec),
measureHeight(heightMeasureSpec));
}

/**
* Determines the width of this view
*
* @param measureSpec
*            A measureSpec packed into an int
* @return The width of the view, honoring constraints from measureSpec
*/
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);

// We were told how big to be
if (specMode == MeasureSpec.EXACTLY) {
result = specSize;
}
// Calculate the width according the views count
else {
int count = 3;
if (viewFlow != null) {
count = viewFlow.getViewsCount();
}
float temp = circleSeparation - 2*radius;
result = (int) (getPaddingLeft() + getPaddingRight()
+ (count * 2 * radius) + (count - 1) * temp + 1);
// Respect AT_MOST value if that was what is called for by
// measureSpec
if (specMode == MeasureSpec.AT_MOST) {
result = Math.min(result, specSize);
}
}
return result;
}

/**
* Determines the height of this view
*
* @param measureSpec
*            A measureSpec packed into an int
* @return The height of the view, honoring constraints from measureSpec
*/
private int measureHeight(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);

// We were told how big to be
if (specMode == MeasureSpec.EXACTLY) {
result = specSize;
}
// Measure the height
else {
result = (int) (2 * radius + getPaddingTop() + getPaddingBottom() + 1);
// Respect AT_MOST value if that was what is called for by
// measureSpec
if (specMode == MeasureSpec.AT_MOST) {
result = Math.min(result, specSize);
}
}
return result;
}

/**
* Sets the fill color
*
* @param color
*            ARGB value for the text
*/
public void setFillColor(int color) {
mPaintActive.setColor(color);
invalidate();
}

/**
* Sets the stroke color
*
* @param color
*            ARGB value for the text
*/
public void setStrokeColor(int color) {
mPaintInactive.setColor(color);
invalidate();
}

/**
* Resets the fade out timer to 0. Creating a new one if needed
*/
private void resetTimer() {
// Only set the timer if we have a timeout of at least 1 millisecond
if (fadeOutTime > 0) {
// Check if we need to create a new timer
if (timer == null || timer._run == false) {
// Create and start a new timer
timer = new FadeTimer();
timer.execute();
} else {
// Reset the current tiemr to 0
timer.resetTimer();
}
}
}

/**
* Counts from 0 to the fade out time and animates the view away when
* reached
*/
private class FadeTimer extends AsyncTask<Void, Void, Void> {
// The current count
private int timer = 0;
// If we are inside the timing loop
private boolean _run = true;

public void resetTimer() {
timer = 0;
}

@Override
protected Void doInBackground(Void... arg0) {
while (_run) {
try {
// Wait for a millisecond
Thread.sleep(1);
// Increment the timer
timer++;

// Check if we've reached the fade out time
if (timer == fadeOutTime) {
// Stop running
_run = false;
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}

@Override
protected void onPostExecute(Void result) {
animation = AnimationUtils.loadAnimation(getContext(),
android.R.anim.fade_out);
animation.setAnimationListener(animationListener);
startAnimation(animation);
}
}

@Override
public void onAnimationEnd(Animation animation) {
setVisibility(View.GONE);
}

@Override
public void onAnimationRepeat(Animation animation) {
}

@Override
public void onAnimationStart(Animation animation) {
}
}

package org.taptwo.android.widget;

import org.taptwo.android.widget.ViewFlow.ViewSwitchListener;

/**
* An interface which defines the contract between a ViewFlow and a
* FlowIndicator.<br/>
* A FlowIndicator is responsible to show an visual indicator on the total views
* number and the current visible view.<br/>
*
*/
public interface FlowIndicator extends ViewSwitchListener {

/**
* Set the current ViewFlow. This method is called by the ViewFlow when the
* FlowIndicator is attached to it.
*
* @param view
*/
public void setViewFlow(ViewFlow view);

/**
* The scroll position has been changed. A FlowIndicator may implement this
* method to reflect the current position
*
* @param h
* @param v
* @param oldh
* @param oldv
*/
public void onScrolled(int h, int v, int oldh, int oldv);
}

<?xml version="1.0" encoding="utf-8"?>

<resources>
<declare-styleable name="ViewFlow">
<attr name="sidebuffer" format="integer" />
</declare-styleable>
<declare-styleable name="CircleFlowIndicator">
<attr name="activeColor" format="color" />
<attr name="inactiveColor" format="color" />
<attr name="radius" format="dimension" />
<attr name="centered" format="boolean" />
<attr name="fadeOut" format="integer" />
<attr name="inactiveType">
<flag name="stroke" value="0" />
<flag name="fill" value="1" />
</attr>
<attr name="activeType">
<flag name="stroke" value="0" />
<flag name="fill" value="1" />
</attr>
<attr name="circleSeparation" format="dimension" />
<attr name="activeRadius" format="dimension" />
</declare-styleable>
</resources>