package com.zwhy.touyuan.widge;  import android.content.Context; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Paint.Align; import android.graphics.PorterDuff; import android.graphics.PorterDuffXfermode; import android.graphics.Rect; import android.util.AttributeSet; import android.view.View;  /**  * 主界面底部选项卡指示器控件，切换时会有图片颜色渐变效果  *  * @author jq  */ public class GradientTab extends View { /** 默认字体大小 */  private static final int DEFAULT_TEXT_SIZE = 12;  /** 图标渐变颜色 */  private static final int DEFAULT_GRADIENT_COLOR = 0xFF45C01A;  /** tab普通状态时字体的颜色 */  private static final int TEXT_COLOR_NORMAL = 0xff878787;  /** tab选中时字体的颜色 */  private static final int TEXT_COLOR_SELECTED = DEFAULT_GRADIENT_COLOR;   /** tab显示的文本 */  private String mTabText = "标题";  /** tab显示的图标 */  private Bitmap mTabIcon;  /** tab显示的字体大小*/  private int mTabTextSize = (int) (getResources().getDisplayMetrics().density * DEFAULT_TEXT_SIZE);  /** 渐变颜色 */  private int mTabGradientColor = DEFAULT_GRADIENT_COLOR;   /** 滑动时图标的透明度 */  private float mAlphaPercent;   /** 渐变的bitmap对象 */  private Bitmap mGradientBitmap;   private Canvas mCanvas;   /** 绘制图标的画笔 */  private Paint mIconPaint;  /** 绘制文本的画笔 */  private Paint mTextPaint = new Paint();   /** 图标的绘制区域 */  private Rect mIconRect = new Rect();  /** 文字的长宽边界范围 */  private Rect mTextBound = new Rect();   public GradientTab(Context context) { super(context);  init();  } public GradientTab(Context context, AttributeSet attrs) { super(context, attrs);  init();  } public void init() { mTextPaint.setTextSize(mTabTextSize);  mTextPaint.setColor(TEXT_COLOR_NORMAL);  mTextPaint.getTextBounds(mTabText, 0, mTabText.length(), mTextBound);  mTextPaint.setAntiAlias(true); // 去矩齿   mRedDotPaint.setAntiAlias(true); // 去锯齿   mUnreadCountPaint.setTextSize(dp2px(12));  mUnreadCountPaint.setAntiAlias(true); // 去锯齿  mUnreadCountPaint.setTextAlign(Align.CENTER); // 居中显示   getUnreadCountTextHeight();  } /** 获取未读条数字体显示高度 */  public void getUnreadCountTextHeight() {
      Rect unreadCountRect = new Rect();  mUnreadCountPaint.getTextBounds("1", 0, 1, unreadCountRect);  mUnreadCountTextHeight = unreadCountRect.height();  } /**  * 测量控件，初始化图标的绘制区域  */  @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec);   // 图标宽高是一样的，取两者的较小值  int iconWidth = Math.min(getMeasuredWidth() - getPaddingLeft()
            - getPaddingRight(), getMeasuredHeight() - getPaddingTop()
            - getPaddingBottom() - mTextBound.height());   int left = getMeasuredWidth() / 2 - iconWidth / 2;  int top = getMeasuredHeight() / 2 - (mTextBound.height() + iconWidth) / 2;   mIconRect.left = left;  mIconRect.top = top;  mIconRect.right = left + iconWidth;  mIconRect.bottom = top + iconWidth;  } @Override  protected void onDraw(Canvas canvas) { // 绘制红点  drawRedDot(canvas, mShowRedDot);   // 绘制未读取条数  drawUnreadCount(canvas, mUnreadCount);   // 绘制tab图标  canvas.drawBitmap(mTabIcon, null, mIconRect, null);   // 绘制tab原文本  drawSourceText(canvas, 0);  int alpha = (int) Math.ceil(255 * mAlphaPercent);   // 内存去准备mBitmap , setAlpha , 纯色 ，xfermode  mGradientBitmap = createGradientBitmap(alpha, mTabGradientColor);   // 绘制渐变色的图标  canvas.drawBitmap(mGradientBitmap, 0, 0, null);   // 绘制渐变色的文本  drawTargetText(canvas, alpha);  } private int dp2px(int dp) { return (int) (dp * getContext().getResources().getDisplayMetrics().density);  } /**  * 绘制变色的文本  *  * @param canvas  * @param alpha  */  private void drawTargetText(Canvas canvas, int alpha) { mTextPaint.setColor(TEXT_COLOR_SELECTED);  mTextPaint.setAlpha(alpha);  int x = (getMeasuredWidth() - mTextBound.width())/ 2;  int y = mIconRect.bottom + mTextBound.height();  canvas.drawText(mTabText, x, y, mTextPaint);  } /**  * 绘制原文本  *  * @param canvas  * @param alpha  */  private void drawSourceText(Canvas canvas, int alpha) { mTextPaint.setColor(TEXT_COLOR_NORMAL);  mTextPaint.setAlpha(255 - alpha);  int x = (getMeasuredWidth()  - mTextBound.width()) / 2;  int y = mIconRect.bottom + mTextBound.height();  canvas.drawText(mTabText, x, y, mTextPaint);  } /**  * 在内存中绘制可变色的Icon  * @param alpha 透明度  * @param gradientColor 渐变色  * @return  */  private Bitmap createGradientBitmap(int alpha, int gradientColor) {
      Canvas canvas = null;  if (mGradientBitmap != null) { mGradientBitmap.recycle();  } mGradientBitmap = Bitmap.createBitmap(getMeasuredWidth(),  getMeasuredHeight(), Config.ARGB_8888);  canvas = new Canvas(mGradientBitmap);  mIconPaint = new Paint();  mIconPaint.setColor(gradientColor);  mIconPaint.setAntiAlias(true); // 去矩齿  mIconPaint.setDither(true);  mIconPaint.setAlpha(alpha); // 透明度  canvas.drawRect(mIconRect, mIconPaint); // 画了一个矩形   mIconPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));   mIconPaint.setAlpha(255);  // 画了图标，图标与短形是重叠的，通过setXfermode()决定出来的效果  canvas.drawBitmap(mTabIcon, null, mIconRect, mIconPaint);  return mGradientBitmap;  } /**  * 更新Tab显示的透明度  * @param alphaPercent 透明度 0 到 1  */  public void updateTabAlpha(float alphaPercent) { this.mAlphaPercent = alphaPercent;  invalidate();  } /**  * 设置Tab的选中状态  *  * @param selected true时显示为高亮, false为正常的显示状态  */  public void setTabSelected(boolean selected) {
      updateTabAlpha(selected ? 1 : 0);  } /**  * 设置要绘制的文本和图标  *  * @param text tab显示的文本  * @param icon tab显示的图标  */  public void setTextAndIcon(String text, int icon) { this.mTabText = text;  this.mTabIcon = BitmapFactory.decodeResource(getResources(), icon);  mTextPaint.getTextBounds(mTabText, 0, mTabText.length(), mTextBound);  invalidate();  } /** 是否显示红点 */  private boolean mShowRedDot = false;   private Paint mRedDotPaint = new Paint();   /**  * 绘制红点提示，传false还未隐藏红点  *  * @param canvas  * @param showRedDot 传true表示绘制红点，传false会清除之前绘制的红点  */  private void drawRedDot(Canvas canvas, boolean showRedDot) { mRedDotPaint.setColor(showRedDot ? Color.RED : Color.TRANSPARENT);  canvas.drawCircle(mIconRect.right, mIconRect.top + dp2px(5), dp2px(5), mRedDotPaint);  } /**  * 显示红点  *  * @param visible true表示显示  */  public void setRedDotVisible(boolean visible) { mShowRedDot = visible;  invalidate();  } private int mUnreadCount;   public void setUnreadCount(int unreadCount) { this.mUnreadCount = unreadCount;  invalidate();  } private Paint mUnreadCountPaint = new Paint();  private int mUnreadCountTextHeight;   public void drawUnreadCount(Canvas canvas, int unreadCount) { boolean showUnreadCount = unreadCount > 0;  mUnreadCountPaint.setColor(showUnreadCount? Color.WHITE : Color.TRANSPARENT);  mRedDotPaint.setColor(showUnreadCount ? Color.RED : Color.TRANSPARENT);   // 未读条数超过两位数时显示三个点...  String text = unreadCount < 100 ? String.valueOf(unreadCount) : "...";  int left = mIconRect.right + dp2px(5);  int top = mIconRect.top + dp2px(9);   canvas.drawCircle(left, top, dp2px(9), mRedDotPaint);  canvas.drawText(text, left, top + mUnreadCountTextHeight / 2, mUnreadCountPaint);  }
}