版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/wanggang514260663/article/details/86437824
相信大家对于词云应该或多或少都有见过，没见过也没关系，这里先给大家看看网络上效果。词云使用python或者javascript实现的话，非常方便，插件也很多，但是android目前还没有见过开源实现。
网络词云效果：http://yciyun.com/
下面是我自己使用canvas实现的词云效果。
实现原理分析
我这里使用的实现原理是使用填格子的方式，下面给一张图来说明。
仔细看这张图，你会发现我画了四个不同大小的文字。四个不同的字体占用了不同大小的表格。
- 最大的字体： 占用4x4
- 二号字体：3x3
- 三号字体：2x2
- 四号字体: 1x1
看到现在你是不是已经有了思路想要动手了，主要是这个思路，接下来就是使用代码填格子，直到格子填满位置。
下面放出来我的实现代码，目前只是按照思路进行了逻辑实现，在填充处理上还是有很多问题，而且没有处理竖直方向。但是由于公司倒闭，所以提前回家了，没有做处理，代码有点糙，一天写出来的东西，没有优化，主要在思路，代码只做参考。
public class WordGroupView extends View {
private static final String TAG = WordGroupView.class.getSimpleName();
//文字绘制画笔
private Paint mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
//辅助线绘制画笔
private Paint mSublinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
private List<DrawPoint> drawPointList = new ArrayList<>();
private List<String> keyWords = new ArrayList<>();
private int[] colors = {
Color.parseColor("#009f9d"),
Color.parseColor("#cd4545"),
Color.parseColor("#7ed3b2"),
Color.parseColor("#d195f9"),
Color.parseColor("#222831"),
Color.parseColor("#b55400"),
};
//文字展示最小可用宽高
private int mMinTextWidth;
private int mMinTextHeight;
//最小可展示文字大小
private int mMinFontSize;
private int[][] mPoints;
private int mMaxXPointCount;
private int mMaxYPointCount;
//设置词条最大长度和最小长度
private int mMaxLength = 0;
private int mMinLength = 0;
public WordGroupView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
mMinFontSize = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 10,
context.getResources().getDisplayMetrics());
mTextPaint.setStyle(Paint.Style.FILL);
mTextPaint.setTextSize(mMinFontSize);
Rect textBound = new Rect();
mTextPaint.getTextBounds("正", 0, 1, textBound);
mMinTextWidth = mMinTextHeight = textBound.width();
Log.e(TAG, mMinTextWidth + "-" + mMinTextHeight);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mMaxXPointCount = w / mMinTextWidth;
mMaxYPointCount = h / mMinTextHeight;
mPoints = new int[mMaxXPointCount][mMaxYPointCount];
for (int i = 0; i < mPoints.length; i++) {
for (int j = 0; j < mPoints[i].length; j++) {
mPoints[i][j] = 0;
}
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.parseColor("#F2F2F2"));
/**
* 绘制辅助线
*/
// for (int i = 0; i <= mMaxXPointCount; i++) {
// canvas.drawLine(i * mMinTextWidth, 0, i * mMinTextWidth, mMinTextHeight * mMaxYPointCount, mSublinePaint);
// }
//
// for (int i = 0; i <= mMaxXPointCount; i++) {
// canvas.drawLine(0, i * mMinTextHeight, mMinTextWidth * mMaxXPointCount, i * mMinTextHeight, mSublinePaint);
// }
//widget=4表示单个文字占用空间为4x4,其他类似
for (int i = 4; i >= 1; i--) {
buildPoints(mPoints, getFullContent(i), i, 0);
}
/**
* 绘制真实的效果
*/
for (DrawPoint point : drawPointList) {
point.draw(canvas);
}
}
private String[] getFullContent(int widget) {
int maxCount = mMaxXPointCount * mMaxYPointCount * widget * widget;
int currMaxItemCount = (int) (Math.random() * maxCount);
String[] maxItems = new String[currMaxItemCount];
for (int i = 0; i < maxItems.length; i++) {
maxItems[i] = keyWords.get((int) (Math.random() * keyWords.size()));
}
if (maxItems.length == 0) {
maxItems = new String[]{
keyWords.get(0)
};
}
return maxItems;
}
/**
* 不断检索并构建指定widget大小的数据，直到不能容纳或者绘制完成
*/
private void buildPoints(int[][] points, String[] maxItems, int widget, int index) {
if ((index > maxItems.length - 1) || capacityOut(points, widget, maxItems[index])) {
return;
}
final int randomPointX = (int) (Math.random() * mMaxXPointCount);
final int randomPointY = (int) (Math.random() * mMaxYPointCount);
boolean isBuildSuc = false;
if (isCanFull(points, randomPointX, randomPointY)
&& isCanDraw(points, randomPointX, randomPointY, maxItems[index], widget)) {
for (int i = randomPointX; i < randomPointX + maxItems[index].length() * widget; i++) {
for (int j = randomPointY; j < randomPointY + widget; j++) {
points[i][j] = 1;
}
}
drawPointList.add(new DrawPoint(randomPointX, randomPointY, maxItems[index], widget));
isBuildSuc = true;
} else {
buildPoints(points, maxItems, widget, index);
}
if (isBuildSuc) {
buildPoints(points, maxItems, widget, index + 1);
}
}
/**
* 超出可容纳范围
*/
private boolean capacityOut(int[][] points, int widget, String maxItem) {
boolean isCapacityOut = true;
for (int i = 0; i < points.length; i++) {
for (int j = 0; j < points[i].length; j++) {
if (isCanDraw(points, i, j, maxItem, widget)) {
isCapacityOut = false;
break;
}
}
}
return isCapacityOut;
}
/**
* 判断是否可以绘制
*/
private boolean isCanDraw(int[][] points, int randomPointX, int randomPointY, String maxItem, int widget) {
boolean isCanFull = false;
if (isOutHorizontal(randomPointX + maxItem.length() * widget)
&& isOutVertical(randomPointY + widget)) {
isCanFull = true;
for (int i = randomPointX; i < randomPointX + maxItem.length() * widget; i++) {
for (int j = randomPointY; j < randomPointY + widget; j++) {
if (!isCanFull(points, i, j)) {
isCanFull = false;
break;
}
}
}
}
return isCanFull;
}
/**
* 判断水平方向是否越界
*/
private boolean isOutHorizontal(int pointX) {
return pointX <= mMaxXPointCount;
}
/**
* 判断竖直方向是否越界
*/
private boolean isOutVertical(int pointY) {
return pointY <= mMaxYPointCount;
}
/**
* 是否可以填充
*/
private boolean isCanFull(int[][] point, int pointX, int pointY) {
if (pointX < mMaxXPointCount && pointY < mMaxYPointCount) {
return point[pointX][pointY] == 0;
}
return false;
}
public void random() {
for (int i = 0; i < mPoints.length; i++) {
for (int j = 0; j < mPoints[i].length; j++) {
mPoints[i][j] = 0;
}
}
drawPointList.clear();
invalidate();
}
public class DrawPoint {
private int pointX;
private int pointY;
public String label;
public int widget;
DrawPoint(int pointX, int pointY, String label, int widget) {
this.pointX = pointX;
this.pointY = pointY;
this.label = label;
this.widget = widget;
}
public void draw(Canvas canvas) {
mTextPaint.setTextSize(mMinFontSize * widget - 8 * widget);
mTextPaint.setColor(colors[(int) (Math.random() * colors.length)]);
Log.e(TAG, widget + "-" + label + "-" + pointX + "-" + pointY);
canvas.drawText(label, pointX * mMinTextWidth + 4 * widget, (pointY + widget) * mMinTextHeight - 4 * widget, mTextPaint);
mTextPaint.setStyle(Paint.Style.FILL);
}
}
public void setWords(List<String> words) {
this.keyWords = words;
for (int i = 0; i < keyWords.size(); i++) {
if (i == 0) {
mMaxLength = keyWords.get(i).length();
mMinLength = keyWords.get(i).length();
continue;
}
if (keyWords.get(i).length() > mMaxLength) {
mMaxLength = keyWords.get(i).length();
}
if (keyWords.get(i).length() < mMinLength) {
mMinLength = keyWords.get(i).length();
}
}
drawPointList.clear();
invalidate();
}
}