公司做一个类似公交站牌的文字竖排效果,自己捉摸了一下,想想估计能实现,就算不能实现,权当学习了。
先看看做出来的效果图:
先说说思路:
整体为绘制圆,绘制间隔线,然后是绘制数字与文字
1.绘制圆和间隔线:
绘制这两个使用了Canvas.drawPath(Path path,Paint paint),因为这样子便于计算,只需要计算Path的路径,其它的就交给canvas可以了,path支持绘制circle(path.addCircle())与绘制line(path.lineto),本来想文本也用path绘制的,不过最后发现绘制文本只有canvas支持,path不支持。剩下的就是计算绘制起始点了
- /**
- * 计算点圆与线轨迹
- */
- private void computeCircleAndLinePath() {
- if (data != null || data.size() != 0) {
- circlePoints = new Point[data.size()];
- circlePaths = new Path[data.size()];
- linePaths = new Path[data.size() - 1];
- //处理文字显示与圆点显示
- //绘制起始偏移量,如果文本高度一半大于半径,则取差值,否则取0
- int offsetX = textHeight / 2 > (circleRadius + circleStokeWidth / 2) ? textHeight / 2 - (circleRadius + circleStokeWidth / 2) : 0;
- //处理paddingLeft
- offsetX += getPaddingLeft();
- for (int i = 0; i < data.size(); i++) {
- Path circlePath = new Path();
- //计算每个圆点的中心点
- int mCircleCenterX = i * lineLength + circleRadius + circleStokeWidth / 2 + offsetX;
- int mCircleCenterY = circleMarginTop + circleRadius;
- circlePoints[i] = new Point(mCircleCenterX, mCircleCenterY);
- //计算圆点路径
- circlePath.addCircle(mCircleCenterX, mCircleCenterY, circleRadius, Path.Direction.CCW);
- circlePaths[i] = circlePath;
- if (i == data.size() - 1) {
- continue;
- }
- //计算线段路径
- Path linePath = new Path();
- //计算线段起始点
- int mlineStartX = mCircleCenterX + circleRadius + circleStokeWidth / 2;
- int mlineEndX = (i + 1) * lineLength + offsetX;
- linePath.moveTo(mlineStartX, mCircleCenterY);
- linePath.lineTo(mlineEndX, mCircleCenterY);
- linePaths[i] = linePath;
- }
- }
- }
/** * 计算点圆与线轨迹 */ private void computeCircleAndLinePath() { if (data != null || data.size() != 0) { circlePoints = new Point[data.size()]; circlePaths = new Path[data.size()]; linePaths = new Path[data.size() - 1]; //处理文字显示与圆点显示 //绘制起始偏移量,如果文本高度一半大于半径,则取差值,否则取0 int offsetX = textHeight / 2 > (circleRadius + circleStokeWidth / 2) ? textHeight / 2 - (circleRadius + circleStokeWidth / 2) : 0; //处理paddingLeft offsetX += getPaddingLeft(); for (int i = 0; i < data.size(); i++) { Path circlePath = new Path(); //计算每个圆点的中心点 int mCircleCenterX = i * lineLength + circleRadius + circleStokeWidth / 2 + offsetX; int mCircleCenterY = circleMarginTop + circleRadius; circlePoints[i] = new Point(mCircleCenterX, mCircleCenterY); //计算圆点路径 circlePath.addCircle(mCircleCenterX, mCircleCenterY, circleRadius, Path.Direction.CCW); circlePaths[i] = circlePath; if (i == data.size() - 1) { continue; } //计算线段路径 Path linePath = new Path(); //计算线段起始点 int mlineStartX = mCircleCenterX + circleRadius + circleStokeWidth / 2; int mlineEndX = (i + 1) * lineLength + offsetX; linePath.moveTo(mlineStartX, mCircleCenterY); linePath.lineTo(mlineEndX, mCircleCenterY); linePaths[i] = linePath; } } }上述代码整体为计算这两个circle与line的起始点,圆的大小,线段的长度都由样式定制来决定,同时记录了每个圆的中心点,每个圆的路径,每个线的路径。
还有一个offsetX,至于这个变量是考虑了因为要定制样式,有字体大于圆的情况,这样的话就会存在文字大小与圆半径之间存在偏移,如果不考虑他,有可能我们的效果会出现第一个条目的文字只显示一半,所以我记录了这个偏移,把他加入了起始点的计算
这里需要注意,android绘制circle时结合了Paint画笔的笔触宽度strokeWidth,为圆半径+strokeWidth/2,所以我们在
Path.addCircle(float x,float y,float radius,Direction dir)时需要考虑传入的半径为设定的圆半径+strokeWidth/2
最后使用canvas绘制即可:
- /**
- * 绘制圆和线段
- */
- private void drawCircleAndLine(Canvas canvas) {
- for (int i = 0; i < circlePaths.length; i++) {
- //改变颜色与风格
- if (i == currSelectedItem) {
- circlePaint.setColor(circleSelectColor);
- circlePaint.setStyle(Paint.Style.FILL_AND_STROKE);
- } else {
- circlePaint.setStyle(Paint.Style.STROKE);
- circlePaint.setColor(circleColor);
- }
- canvas.drawPath(circlePaths[i], circlePaint);
- }
- for (int i = 0; i < linePaths.length; i++) {
- canvas.drawPath(linePaths[i], linePaint);
- }
- }
/** * 绘制圆和线段 */ private void drawCircleAndLine(Canvas canvas) { for (int i = 0; i < circlePaths.length; i++) { //改变颜色与风格 if (i == currSelectedItem) { circlePaint.setColor(circleSelectColor); circlePaint.setStyle(Paint.Style.FILL_AND_STROKE); } else { circlePaint.setStyle(Paint.Style.STROKE); circlePaint.setColor(circleColor); } canvas.drawPath(circlePaths[i], circlePaint); } for (int i = 0; i < linePaths.length; i++) { canvas.drawPath(linePaths[i], linePaint); } }
2.绘制数字和文本:
因为Path不能绘制文本,只能用canvas来绘制,canvas提供了大概三种类型的方法:
canvas.drawText();
canvas.drawPostText();(已废弃)
canvas.drawTextonPath() 该方法不好控制文本的方向以及文本的样式
所以采用drawText()方法
- /**
- * 绘制数字和文本
- */
- private void drawNumberAndItemText(Canvas canvas) {
- for (int i = 0; i < data.size(); i++) {
- //数字绘制起始点
- int mNumberStartX = circlePoints[i].x;
- int mNumberStartY = circlePoints[i].y + circleRadius + numberMarginTop;
- //测量数字宽度
- float textWidth = numberPaint.measureText(String.valueOf(i + 1), 0, String.valueOf(i + 1).length());
- //改变颜色
- if (i == currSelectedItem) {
- numberPaint.setColor(numberSelectColor);
- } else {
- numberPaint.setColor(numberColor);
- }
- canvas.drawText(String.valueOf(i + 1), mNumberStartX - textWidth / 2, mNumberStartY, numberPaint);
- drawItemText(canvas);
- }
- }
/** * 绘制数字和文本 */ private void drawNumberAndItemText(Canvas canvas) { for (int i = 0; i < data.size(); i++) { //数字绘制起始点 int mNumberStartX = circlePoints[i].x; int mNumberStartY = circlePoints[i].y + circleRadius + numberMarginTop; //测量数字宽度 float textWidth = numberPaint.measureText(String.valueOf(i + 1), 0, String.valueOf(i + 1).length()); //改变颜色 if (i == currSelectedItem) { numberPaint.setColor(numberSelectColor); } else { numberPaint.setColor(numberColor); } canvas.drawText(String.valueOf(i + 1), mNumberStartX - textWidth / 2, mNumberStartY, numberPaint); drawItemText(canvas); } }因为为竖直排列,所以要判断每个字的宽度,高度,同时还的考虑每个字之间的间隔,所以确定每个字的范围很有必要
- /**
- * 绘制文本
- */
- private void drawItemText(Canvas canvas) {
- //记录每个条目区域
- textRegions = new Region[data.size()];
- for (int i = 0; i < data.size(); i++) {
- Region region = new Region();
- int mItemStartX = circlePoints[i].x;
- int mItemStartY = circlePoints[i].y + circleRadius + numberMarginTop + textMarginTop;
- String text = data.get(i);
- char[] chars = text.toCharArray();
- //每个条目区域的计算
- Rect textArea = new Rect();
- textArea.left = mItemStartX - textHeight / 2;
- textArea.right = textArea.left + textHeight;
- //减去一个文字高度,因为绘制文字是在baseline上方绘制,基线位置为drawText(text,x,y,paint)的y位置
- textArea.top = mItemStartY - textHeight;
- int lastTextHeight = 0;
- //改变颜色
- if (i == currSelectedItem) {
- textPaint.setColor(textSelectColor);
- } else {
- textPaint.setColor(textColor);
- }
- for (int j = 0; j < chars.length; j++) {
- canvas.drawText(String.valueOf(text.charAt(j)), mItemStartX - textHeight / 2, mItemStartY + lastTextHeight, textPaint);
- lastTextHeight += textHeight + textSpace;
- }
- //此处减去最后一个文字间隔
- textArea.bottom = textArea.top + lastTextHeight - textSpace;
- region.set(textArea);
- textRegions[i] = region;
- }
- }
/** * 绘制文本 */ private void drawItemText(Canvas canvas) { //记录每个条目区域 textRegions = new Region[data.size()]; for (int i = 0; i < data.size(); i++) { Region region = new Region(); int mItemStartX = circlePoints[i].x; int mItemStartY = circlePoints[i].y + circleRadius + numberMarginTop + textMarginTop; String text = data.get(i); char[] chars = text.toCharArray(); //每个条目区域的计算 Rect textArea = new Rect(); textArea.left = mItemStartX - textHeight / 2; textArea.right = textArea.left + textHeight; //减去一个文字高度,因为绘制文字是在baseline上方绘制,基线位置为drawText(text,x,y,paint)的y位置 textArea.top = mItemStartY - textHeight; int lastTextHeight = 0; //改变颜色 if (i == currSelectedItem) { textPaint.setColor(textSelectColor); } else { textPaint.setColor(textColor); } for (int j = 0; j < chars.length; j++) { canvas.drawText(String.valueOf(text.charAt(j)), mItemStartX - textHeight / 2, mItemStartY + lastTextHeight, textPaint); lastTextHeight += textHeight + textSpace; } //此处减去最后一个文字间隔 textArea.bottom = textArea.top + lastTextHeight - textSpace; region.set(textArea); textRegions[i] = region; } }
文本的宽度,高度可以采用如下方法获得:
- /**
- * 计算文本信息,包含每个条目的宽度,高度
- */
- private Rect getTextInfo(String text, Paint paint) {
- Rect mrect = new Rect();
- //获得文本的最小矩形大小,也是测量文本高度,宽度的一种方法
- paint.getTextBounds(text, 0, text.length(), mrect);
- return mrect;
- }
/** * 计算文本信息,包含每个条目的宽度,高度 */ private Rect getTextInfo(String text, Paint paint) { Rect mrect = new Rect(); //获得文本的最小矩形大小,也是测量文本高度,宽度的一种方法 paint.getTextBounds(text, 0, text.length(), mrect); return mrect; }
文本宽度也可以使用Paint.measureText(String text,int start,int end)获得
这里需要注意:
android绘制文字的时候,使用drawText(String text,float x,float y,Paint paint)时,大家注意y坐标的位置实际上为绘制文字的baseline位置,在基线位置之上开始绘制
最后因为在布局文件使用了scrollView,torizontalScrollView,所以在View.onMeasure()计算了整个view占据的最小空间大小,如果不这样计算,在绘制view的时候会无法显示,因为scrollview传递给子布局的大小为0
- @Override
- protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
- //此处为与HorizontalScrollView搭配使用,达到滑动目的,别的滑动方式请修改此处代码或者删除
- int mViewWidth = getPaddingLeft() + getPaddingRight() + computeMinViewWidth();
- int mViewHeight = getPaddingBottom() + getPaddingTop() + computeMinViewHeight();
- setMeasuredDimension(mViewWidth, mViewHeight);
- }
@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { //此处为与HorizontalScrollView搭配使用,达到滑动目的,别的滑动方式请修改此处代码或者删除 int mViewWidth = getPaddingLeft() + getPaddingRight() + computeMinViewWidth(); int mViewHeight = getPaddingBottom() + getPaddingTop() + computeMinViewHeight(); setMeasuredDimension(mViewWidth, mViewHeight); }
- /**
- * 计算View最小宽度
- */
- private int computeMinViewWidth() {
- int viewWidth = 0;
- if (data != null || data.size() != 0) {
- //计算文本高度,起始不管第一条是否为空,高度都会与其它文本保持一致
- Rect textRect = getTextInfo(data.get(0), textPaint);
- textHeight = textRect.height();
- viewWidth = (data.size() - 1) * lineLength + 2 * circleRadius + circleStokeWidth;
- if (textHeight > (2 * circleRadius + circleStokeWidth)) {
- int offsetX = textHeight / 2 - (circleRadius + circleStokeWidth / 2);
- viewWidth = viewWidth + 2 * offsetX;
- }
- }
- return viewWidth;
- }
- /**
- * 计算View最小高度
- */
- private int computeMinViewHeight() {
- int viewHeight = 0;
- if (data != null || data.size() != 0) {
- String maxText = "";
- for (int i = 0; i < data.size(); i++) {
- //计算文本宽度
- maxText = data.get(i).length() > maxText.length() ? data.get(i) : maxText;
- }
- //获得总文本间距
- int textSpaceWidth = textSpace * (maxText.length() - 1);
- Rect textRect = getTextInfo(maxText, textPaint);
- //最大文本高度
- int textMaxHeight = textRect.width() + textSpaceWidth;
- //计算ViewHeight
- viewHeight = textMaxHeight + textMarginTop + numberMarginTop + (2 * circleRadius + circleStokeWidth) + circleMarginTop;
- }
- return viewHeight;
- }
/** * 计算View最小宽度 */ private int computeMinViewWidth() { int viewWidth = 0; if (data != null || data.size() != 0) { //计算文本高度,起始不管第一条是否为空,高度都会与其它文本保持一致 Rect textRect = getTextInfo(data.get(0), textPaint); textHeight = textRect.height(); viewWidth = (data.size() - 1) * lineLength + 2 * circleRadius + circleStokeWidth; if (textHeight > (2 * circleRadius + circleStokeWidth)) { int offsetX = textHeight / 2 - (circleRadius + circleStokeWidth / 2); viewWidth = viewWidth + 2 * offsetX; } } return viewWidth; } /** * 计算View最小高度 */ private int computeMinViewHeight() { int viewHeight = 0; if (data != null || data.size() != 0) { String maxText = ""; for (int i = 0; i < data.size(); i++) { //计算文本宽度 maxText = data.get(i).length() > maxText.length() ? data.get(i) : maxText; } //获得总文本间距 int textSpaceWidth = textSpace * (maxText.length() - 1); Rect textRect = getTextInfo(maxText, textPaint); //最大文本高度 int textMaxHeight = textRect.width() + textSpaceWidth; //计算ViewHeight viewHeight = textMaxHeight + textMarginTop + numberMarginTop + (2 * circleRadius + circleStokeWidth) + circleMarginTop; } return viewHeight; }
大概就是这样子,基本上都是一点点绘制的,暂时没有想到别的办法,如有好的思路,请提供
下面附上源码下载地址:
http://download.csdn.net/download/kongzuoding/9403338
大家可以下载看看效果,如有错误,或者更好的建议,请指出