android 跑马灯 焦点,【Android】不依赖焦点和选中的TextView跑马灯

【Android】不依赖焦点和选中的TextView跑马灯

来源：互联网 作者：佚名 时间：2015-06-27 23:51

承TextView，并仿照源码修改而来，主要是取消了焦点和选中了判断，也不依赖文本的宽度。 import java.lang.ref.WeakReference;import android.content.Context;import android.graphics.Canvas;import android.os.Handler;import android.os.Message;import

承TextView，并仿照源码修改而来，主要是取消了焦点和选中了判断，也不依赖文本的宽度。import java.lang.ref.WeakReference;

import android.content.Context;

import android.graphics.Canvas;

import android.os.Handler;

import android.os.Message;

import android.util.AttributeSet;

import android.widget.TextView;

public class MarqueeTextView extends TextView {

private Marquee mMarquee;

public MarqueeTextView(Context context, AttributeSet attrs) {

super(context, attrs);

}

public MarqueeTextView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

}

public MarqueeTextView(Context context) {

super(context);

}

public void startMarquee() {

startMarquee(-1);

}

public void startMarquee(int repeatLimit) {

if (mMarquee == null)

mMarquee = new Marquee(this);

mMarquee.start(repeatLimit);

}

public void stopMarquee() {

if (mMarquee != null && !mMarquee.isStopped()) {

mMarquee.stop();

}

}

public void toggleMarquee() {

if (mMarquee == null || mMarquee.isStopped())

startMarquee();

else

stopMarquee();

}

@Override

protected void onDraw(Canvas canvas) {

if (mMarquee != null && mMarquee.isRunning()) {

final float dx = -mMarquee.getScroll();

canvas.translate(getLayoutDirection() == LAYOUT_DIRECTION_RTL ? -dx

: +dx, 0.0f);

}

super.onDraw(canvas);

}

@SuppressWarnings("unused")

private static final class Marquee extends Handler {

// TODO: Add an option to configure this

private static final float MARQUEE_DELTA_MAX = 0.07f;

private static final int MARQUEE_DELAY = 0;// 1200;

private static final int MARQUEE_RESTART_DELAY = 1200;

private static final int MARQUEE_RESOLUTION = 1000 / 30;

private static final int MARQUEE_PIXELS_PER_SECOND = 30;

private static final byte MARQUEE_STOPPED = 0x0;

private static final byte MARQUEE_STARTING = 0x1;

private static final byte MARQUEE_RUNNING = 0x2;

private static final int MESSAGE_START = 0x1;

private static final int MESSAGE_TICK = 0x2;

private static final int MESSAGE_RESTART = 0x3;

private final WeakReference mView;

private byte mStatus = MARQUEE_STOPPED;

private final float mScrollUnit;

private float mMaxScroll;

private float mMaxFadeScroll;

private float mGhostStart;

private float mGhostOffset;

private float mFadeStop;

private int mRepeatLimit;

private float mScroll;

Marquee(TextView v) {

final float density = v.getContext().getResources()

.getDisplayMetrics().density;

mScrollUnit = (MARQUEE_PIXELS_PER_SECOND * density)

/ MARQUEE_RESOLUTION;

mView = new WeakReference(v);

}

@Override

public void handleMessage(Message msg) {

switch (msg.what) {

case MESSAGE_START:

mStatus = MARQUEE_RUNNING;

tick();

break;

case MESSAGE_TICK:

tick();

break;

case MESSAGE_RESTART:

if (mStatus == MARQUEE_RUNNING) {

if (mRepeatLimit >= 0) {

mRepeatLimit--;

}

start(mRepeatLimit);

}

break;

}

}

void tick() {

if (mStatus != MARQUEE_RUNNING) {

return;

}

removeMessages(MESSAGE_TICK);

final TextView textView = mView.get();

// && (textView.isFocused() || textView.isSelected())

if (textView != null) {

mScroll += mScrollUnit;

if (mScroll > mMaxScroll) {

mScroll = mMaxScroll;

sendEmptyMessageDelayed(MESSAGE_RESTART,

MARQUEE_RESTART_DELAY);

} else {

sendEmptyMessageDelayed(MESSAGE_TICK, MARQUEE_RESOLUTION);

}

textView.invalidate();

}

}

void stop() {

mStatus = MARQUEE_STOPPED;

removeMessages(MESSAGE_START);

removeMessages(MESSAGE_RESTART);

removeMessages(MESSAGE_TICK);

resetScroll();

}

private void resetScroll() {

mScroll = 0.0f;

final TextView textView = mView.get();

if (textView != null) {

textView.invalidate();

}

}

void start(int repeatLimit) {

if (repeatLimit == 0) {

stop();

return;

}

mRepeatLimit = repeatLimit;

final TextView textView = mView.get();

if (textView != null && textView.getLayout() != null) {

mStatus = MARQUEE_STARTING;

mScroll = 0.0f;

final int textWidth = textView.getWidth()

- textView.getCompoundPaddingLeft()

- textView.getCompoundPaddingRight();

final float lineWidth = textView.getLayout().getLineWidth(0);

final float gap = textWidth / 3.0f;

mGhostStart = lineWidth - textWidth + gap;

mMaxScroll = mGhostStart + textWidth;

mGhostOffset = lineWidth + gap;

mFadeStop = lineWidth + textWidth / 6.0f;

mMaxFadeScroll = mGhostStart + lineWidth + lineWidth;

textView.invalidate();

sendEmptyMessageDelayed(MESSAGE_START, MARQUEE_DELAY);

}

}

float getGhostOffset() {

return mGhostOffset;

}

float getScroll() {

return mScroll;

}

float getMaxFadeScroll() {

return mMaxFadeScroll;

}

boolean shouldDrawLeftFade() {

return mScroll <= mFadeStop;

}

boolean shouldDrawGhost() {

return mStatus == MARQUEE_RUNNING && mScroll > mGhostStart;

}

boolean isRunning() {

return mStatus == MARQUEE_RUNNING;

}

boolean isStopped() {

return mStatus == MARQUEE_STOPPED;

}

}

}

代码说明：

1、取消了焦点和选中的判断

2、将延迟1200改为0，，立即执行跑马灯效果。

3、核心代码都是直接从TextView拷贝出来。

结束

这里主要是提供一种解决问题的思路，实际使用还需要进行相应的修改。