简单几步教你实现对 Drawable 的扇形区域剪切显示

/* * Copyright (C) 2014 Kifile(kifile@kifile.com) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE⑵.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.kifile.graphics; import android.content.res.ColorStateList; import android.graphics.*; import android.graphics.drawable.Drawable; /** * Created by kifile on 14/10/31. */ public class SectorDrawable extends Drawable implements Drawable.Callback { private Drawable mDrawable; private Path mPath = new Path(); private float mPercent; public SectorDrawable(Drawable drawable) { this.mDrawable = drawable; if (drawable != null) { drawable.setCallback(this); } } @Override public int getChangingConfigurations() { return super.getChangingConfigurations() | mDrawable.getChangingConfigurations(); } @Override public boolean getPadding(Rect padding) { return mDrawable.getPadding(padding); } @Override public boolean setVisible(boolean visible, boolean restart) { mDrawable.setVisible(visible, restart); return super.setVisible(visible, restart); } @Override public void draw(Canvas canvas) { mPath.reset(); RectF rect = new RectF(getBounds()); double radius = Math.pow(Math.pow(rect.right, 2) + Math.pow(rect.bottom, 2), 0.5); mPath.moveTo(rect.right / 2, rect.bottom / 2); mPath.lineTo(rect.right / 2, 0); if (mPercent > 0.125f) { mPath.lineTo(rect.right, 0); } if (mPercent > 0.375f) { mPath.lineTo(rect.right, rect.bottom); } if (mPercent > 0.625f) { mPath.lineTo(0, rect.bottom); } if (mPercent > 0.875f) { mPath.lineTo(0, 0); } mPath.lineTo((float) (rect.right / 2 + radius * Math.sin(Math.PI * 2 * mPercent)), (float) (rect.bottom / 2 - radius * Math.cos(Math.PI * 2 * mPercent))); mPath.close(); if (mPercent >= 0 && mPercent <= 1) { canvas.save(); canvas.clipPath(mPath); mDrawable.draw(canvas); canvas.restore(); } } @Override public void setAlpha(int alpha) { mDrawable.setAlpha(alpha); } @Override public int getAlpha() { return mDrawable.getAlpha(); } @Override public void setColorFilter(ColorFilter cf) { mDrawable.setColorFilter(cf); } @Override public void setTintList(ColorStateList tint) { mDrawable.setTintList(tint); } @Override public void setTintMode(PorterDuff.Mode tintMode) { mDrawable.setTintMode(tintMode); } @Override public int getOpacity() { // TODO Auto-generated method stub return mDrawable.getOpacity(); } @Override public boolean isStateful() { // TODO Auto-generated method stub return mDrawable.isStateful(); } @Override protected boolean onStateChange(int[] state) { return mDrawable.setState(state); } @Override protected boolean onLevelChange(int level) { mDrawable.setLevel(level); invalidateSelf(); return true; } @Override protected void onBoundsChange(Rect bounds) { mDrawable.setBounds(bounds); } @Override public int getIntrinsicHeight() { return mDrawable.getIntrinsicHeight(); } @Override public int getIntrinsicWidth() { return mDrawable.getIntrinsicWidth(); } /** * 显示的区域范围 * * @param percent 0至1 */ public void setPercent(float percent) { if (percent > 1) { percent = 1; } else if (percent < 0) { percent = 0; } if (percent != mPercent) { this.mPercent = percent; invalidateSelf(); } } @Override public void invalidateDrawable(Drawable who) { final Callback callback = getCallback(); if (callback != null) { callback.invalidateDrawable(this); } } @Override public void scheduleDrawable(Drawable who, Runnable what, long when) { final Callback callback = getCallback(); if (callback != null) { callback.scheduleDrawable(this, what, when); } } @Override public void unscheduleDrawable(Drawable who, Runnable what) { final Callback callback = getCallback(); if (callback != null) { callback.unscheduleDrawable(this, what); } } }

ImageView img = (ImageView) findViewById(R.id.sector_img); mDrawable = new SectorDrawable(img.getDrawable()); img.setImageDrawable(mDrawable);

mDrawable.setPercent(percent);

/* * Copyright (C) 2014 Kifile(kifile@kifile.com) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE⑵.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.kifile.sample.app; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v7.app.ActionBarActivity; import android.util.Log; import android.view.Menu; import android.view.MenuItem; import android.widget.ImageView; import com.kifile.graphics.SectorDrawable; public class MainActivity extends ActionBarActivity { private SectorDrawable mDrawable; private Handler mHandler = new Handler() { private float percent; @Override public void handleMessage(Message msg) { super.handleMessage(msg); if (percent <= 1) { percent += 0.01; } else { percent = 0; return; } mDrawable.setPercent(percent); Log.i("this",String.valueOf(percent)); sendEmptyMessageDelayed(0, 10); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ImageView img = (ImageView) findViewById(R.id.sector_img); mDrawable = new SectorDrawable(img.getDrawable()); img.setImageDrawable(mDrawable); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { mHandler.sendEmptyMessage(0); return true; } return super.onOptionsItemSelected(item); } }