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Charting library for Android compatible with API 8+(Android 2.2).
The newest version!
package lecho.lib.hellocharts.renderer;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Cap;
import android.graphics.Path;
import android.graphics.PorterDuff.Mode;
import android.graphics.Rect;
import lecho.lib.hellocharts.model.Line;
import lecho.lib.hellocharts.model.LineChartData;
import lecho.lib.hellocharts.model.PointValue;
import lecho.lib.hellocharts.model.SelectedValue.SelectedValueType;
import lecho.lib.hellocharts.model.ValueShape;
import lecho.lib.hellocharts.model.Viewport;
import lecho.lib.hellocharts.provider.LineChartDataProvider;
import lecho.lib.hellocharts.util.ChartUtils;
import lecho.lib.hellocharts.view.Chart;
/**
* Renderer for line chart. Can draw lines, cubic lines, filled area chart and scattered chart.
*/
public class LineChartRenderer extends AbstractChartRenderer {
private static final float LINE_SMOOTHNESS = 0.16f;
private static final int DEFAULT_LINE_STROKE_WIDTH_DP = 3;
private static final int DEFAULT_TOUCH_TOLERANCE_MARGIN_DP = 4;
private static final int MODE_DRAW = 0;
private static final int MODE_HIGHLIGHT = 1;
private LineChartDataProvider dataProvider;
private int checkPrecision;
private float baseValue;
private int touchToleranceMargin;
private Path path = new Path();
private Paint linePaint = new Paint();
private Paint pointPaint = new Paint();
private Bitmap softwareBitmap;
private Canvas softwareCanvas = new Canvas();
private Viewport tempMaximumViewport = new Viewport();
public LineChartRenderer(Context context, Chart chart, LineChartDataProvider dataProvider) {
super(context, chart);
this.dataProvider = dataProvider;
touchToleranceMargin = ChartUtils.dp2px(density, DEFAULT_TOUCH_TOLERANCE_MARGIN_DP);
linePaint.setAntiAlias(true);
linePaint.setStyle(Paint.Style.STROKE);
linePaint.setStrokeCap(Cap.ROUND);
linePaint.setStrokeWidth(ChartUtils.dp2px(density, DEFAULT_LINE_STROKE_WIDTH_DP));
pointPaint.setAntiAlias(true);
pointPaint.setStyle(Paint.Style.FILL);
checkPrecision = ChartUtils.dp2px(density, 2);
}
public void onChartSizeChanged() {
final int internalMargin = calculateContentRectInternalMargin();
computator.insetContentRectByInternalMargins(internalMargin, internalMargin,
internalMargin, internalMargin);
if (computator.getChartWidth() > 0 && computator.getChartHeight() > 0) {
softwareBitmap = Bitmap.createBitmap(computator.getChartWidth(), computator.getChartHeight(),
Bitmap.Config.ARGB_8888);
softwareCanvas.setBitmap(softwareBitmap);
}
}
@Override
public void onChartDataChanged() {
super.onChartDataChanged();
final int internalMargin = calculateContentRectInternalMargin();
computator.insetContentRectByInternalMargins(internalMargin, internalMargin,
internalMargin, internalMargin);
baseValue = dataProvider.getLineChartData().getBaseValue();
onChartViewportChanged();
}
@Override
public void onChartViewportChanged() {
if (isViewportCalculationEnabled) {
calculateMaxViewport();
computator.setMaxViewport(tempMaximumViewport);
computator.setCurrentViewport(computator.getMaximumViewport());
}
}
@Override
public void draw(Canvas canvas) {
final LineChartData data = dataProvider.getLineChartData();
final Canvas drawCanvas;
// softwareBitmap can be null if chart is rendered in layout editor. In that case use default canvas and not
// softwareCanvas.
if (null != softwareBitmap) {
drawCanvas = softwareCanvas;
drawCanvas.drawColor(Color.TRANSPARENT, Mode.CLEAR);
} else {
drawCanvas = canvas;
}
for (Line line : data.getLines()) {
if (line.hasLines()) {
if (line.isCubic()) {
drawSmoothPath(drawCanvas, line);
} else if (line.isSquare()) {
drawSquarePath(drawCanvas, line);
} else {
drawPath(drawCanvas, line);
}
}
}
if (null != softwareBitmap) {
canvas.drawBitmap(softwareBitmap, 0, 0, null);
}
}
@Override
public void drawUnclipped(Canvas canvas) {
final LineChartData data = dataProvider.getLineChartData();
int lineIndex = 0;
for (Line line : data.getLines()) {
if (checkIfShouldDrawPoints(line)) {
drawPoints(canvas, line, lineIndex, MODE_DRAW);
}
++lineIndex;
}
if (isTouched()) {
// Redraw touched point to bring it to the front
highlightPoints(canvas);
}
}
private boolean checkIfShouldDrawPoints(Line line) {
return line.hasPoints() || line.getValues().size() == 1;
}
@Override
public boolean checkTouch(float touchX, float touchY) {
selectedValue.clear();
final LineChartData data = dataProvider.getLineChartData();
int lineIndex = 0;
for (Line line : data.getLines()) {
if (checkIfShouldDrawPoints(line)) {
int pointRadius = ChartUtils.dp2px(density, line.getPointRadius());
int valueIndex = 0;
for (PointValue pointValue : line.getValues()) {
final float rawValueX = computator.computeRawX(pointValue.getX());
final float rawValueY = computator.computeRawY(pointValue.getY());
if (isInArea(rawValueX, rawValueY, touchX, touchY, pointRadius + touchToleranceMargin)) {
selectedValue.set(lineIndex, valueIndex, SelectedValueType.LINE);
}
++valueIndex;
}
}
++lineIndex;
}
return isTouched();
}
private void calculateMaxViewport() {
tempMaximumViewport.set(Float.MAX_VALUE, Float.MIN_VALUE, Float.MIN_VALUE, Float.MAX_VALUE);
LineChartData data = dataProvider.getLineChartData();
for (Line line : data.getLines()) {
// Calculate max and min for viewport.
for (PointValue pointValue : line.getValues()) {
if (pointValue.getX() < tempMaximumViewport.left) {
tempMaximumViewport.left = pointValue.getX();
}
if (pointValue.getX() > tempMaximumViewport.right) {
tempMaximumViewport.right = pointValue.getX();
}
if (pointValue.getY() < tempMaximumViewport.bottom) {
tempMaximumViewport.bottom = pointValue.getY();
}
if (pointValue.getY() > tempMaximumViewport.top) {
tempMaximumViewport.top = pointValue.getY();
}
}
}
}
private int calculateContentRectInternalMargin() {
int contentAreaMargin = 0;
final LineChartData data = dataProvider.getLineChartData();
for (Line line : data.getLines()) {
if (checkIfShouldDrawPoints(line)) {
int margin = line.getPointRadius() + DEFAULT_TOUCH_TOLERANCE_MARGIN_DP;
if (margin > contentAreaMargin) {
contentAreaMargin = margin;
}
}
}
return ChartUtils.dp2px(density, contentAreaMargin);
}
/**
* Draws lines, uses path for drawing filled area on software canvas. Line is drawn with canvas.drawLines() method.
*/
private void drawPath(Canvas canvas, final Line line) {
prepareLinePaint(line);
int valueIndex = 0;
for (PointValue pointValue : line.getValues()) {
final float rawX = computator.computeRawX(pointValue.getX());
final float rawY = computator.computeRawY(pointValue.getY());
if (valueIndex == 0) {
path.moveTo(rawX, rawY);
} else {
path.lineTo(rawX, rawY);
}
++valueIndex;
}
canvas.drawPath(path, linePaint);
if (line.isFilled()) {
drawArea(canvas, line);
}
path.reset();
}
private void drawSquarePath(Canvas canvas, final Line line) {
prepareLinePaint(line);
int valueIndex = 0;
float previousRawY = 0;
for (PointValue pointValue : line.getValues()) {
final float rawX = computator.computeRawX(pointValue.getX());
final float rawY = computator.computeRawY(pointValue.getY());
if (valueIndex == 0) {
path.moveTo(rawX, rawY);
} else {
path.lineTo(rawX, previousRawY);
path.lineTo(rawX, rawY);
}
previousRawY = rawY;
++valueIndex;
}
canvas.drawPath(path, linePaint);
if (line.isFilled()) {
drawArea(canvas, line);
}
path.reset();
}
private void drawSmoothPath(Canvas canvas, final Line line) {
prepareLinePaint(line);
final int lineSize = line.getValues().size();
float prePreviousPointX = Float.NaN;
float prePreviousPointY = Float.NaN;
float previousPointX = Float.NaN;
float previousPointY = Float.NaN;
float currentPointX = Float.NaN;
float currentPointY = Float.NaN;
float nextPointX = Float.NaN;
float nextPointY = Float.NaN;
for (int valueIndex = 0; valueIndex < lineSize; ++valueIndex) {
if (Float.isNaN(currentPointX)) {
PointValue linePoint = line.getValues().get(valueIndex);
currentPointX = computator.computeRawX(linePoint.getX());
currentPointY = computator.computeRawY(linePoint.getY());
}
if (Float.isNaN(previousPointX)) {
if (valueIndex > 0) {
PointValue linePoint = line.getValues().get(valueIndex - 1);
previousPointX = computator.computeRawX(linePoint.getX());
previousPointY = computator.computeRawY(linePoint.getY());
} else {
previousPointX = currentPointX;
previousPointY = currentPointY;
}
}
if (Float.isNaN(prePreviousPointX)) {
if (valueIndex > 1) {
PointValue linePoint = line.getValues().get(valueIndex - 2);
prePreviousPointX = computator.computeRawX(linePoint.getX());
prePreviousPointY = computator.computeRawY(linePoint.getY());
} else {
prePreviousPointX = previousPointX;
prePreviousPointY = previousPointY;
}
}
// nextPoint is always new one or it is equal currentPoint.
if (valueIndex < lineSize - 1) {
PointValue linePoint = line.getValues().get(valueIndex + 1);
nextPointX = computator.computeRawX(linePoint.getX());
nextPointY = computator.computeRawY(linePoint.getY());
} else {
nextPointX = currentPointX;
nextPointY = currentPointY;
}
if (valueIndex == 0) {
// Move to start point.
path.moveTo(currentPointX, currentPointY);
} else {
// Calculate control points.
final float firstDiffX = (currentPointX - prePreviousPointX);
final float firstDiffY = (currentPointY - prePreviousPointY);
final float secondDiffX = (nextPointX - previousPointX);
final float secondDiffY = (nextPointY - previousPointY);
final float firstControlPointX = previousPointX + (LINE_SMOOTHNESS * firstDiffX);
final float firstControlPointY = previousPointY + (LINE_SMOOTHNESS * firstDiffY);
final float secondControlPointX = currentPointX - (LINE_SMOOTHNESS * secondDiffX);
final float secondControlPointY = currentPointY - (LINE_SMOOTHNESS * secondDiffY);
path.cubicTo(firstControlPointX, firstControlPointY, secondControlPointX, secondControlPointY,
currentPointX, currentPointY);
}
// Shift values by one back to prevent recalculation of values that have
// been already calculated.
prePreviousPointX = previousPointX;
prePreviousPointY = previousPointY;
previousPointX = currentPointX;
previousPointY = currentPointY;
currentPointX = nextPointX;
currentPointY = nextPointY;
}
canvas.drawPath(path, linePaint);
if (line.isFilled()) {
drawArea(canvas, line);
}
path.reset();
}
private void prepareLinePaint(final Line line) {
linePaint.setStrokeWidth(ChartUtils.dp2px(density, line.getStrokeWidth()));
linePaint.setColor(line.getColor());
linePaint.setPathEffect(line.getPathEffect());
}
// TODO Drawing points can be done in the same loop as drawing lines but it
// may cause problems in the future with
// implementing point styles.
private void drawPoints(Canvas canvas, Line line, int lineIndex, int mode) {
pointPaint.setColor(line.getPointColor());
int valueIndex = 0;
for (PointValue pointValue : line.getValues()) {
int pointRadius = ChartUtils.dp2px(density, line.getPointRadius());
final float rawX = computator.computeRawX(pointValue.getX());
final float rawY = computator.computeRawY(pointValue.getY());
if (computator.isWithinContentRect(rawX, rawY, checkPrecision)) {
// Draw points only if they are within contentRectMinusAllMargins, using contentRectMinusAllMargins
// instead of viewport to avoid some
// float rounding problems.
if (MODE_DRAW == mode) {
drawPoint(canvas, line, pointValue, rawX, rawY, pointRadius);
if (line.hasLabels()) {
drawLabel(canvas, line, pointValue, rawX, rawY, pointRadius + labelOffset);
}
} else if (MODE_HIGHLIGHT == mode) {
highlightPoint(canvas, line, pointValue, rawX, rawY, lineIndex, valueIndex);
} else {
throw new IllegalStateException("Cannot process points in mode: " + mode);
}
}
++valueIndex;
}
}
private void drawPoint(Canvas canvas, Line line, PointValue pointValue, float rawX, float rawY,
float pointRadius) {
if (ValueShape.SQUARE.equals(line.getShape())) {
canvas.drawRect(rawX - pointRadius, rawY - pointRadius, rawX + pointRadius, rawY + pointRadius,
pointPaint);
} else if (ValueShape.CIRCLE.equals(line.getShape())) {
canvas.drawCircle(rawX, rawY, pointRadius, pointPaint);
} else if (ValueShape.DIAMOND.equals(line.getShape())) {
canvas.save();
canvas.rotate(45, rawX, rawY);
canvas.drawRect(rawX - pointRadius, rawY - pointRadius, rawX + pointRadius, rawY + pointRadius,
pointPaint);
canvas.restore();
} else {
throw new IllegalArgumentException("Invalid point shape: " + line.getShape());
}
}
private void highlightPoints(Canvas canvas) {
int lineIndex = selectedValue.getFirstIndex();
Line line = dataProvider.getLineChartData().getLines().get(lineIndex);
drawPoints(canvas, line, lineIndex, MODE_HIGHLIGHT);
}
private void highlightPoint(Canvas canvas, Line line, PointValue pointValue, float rawX, float rawY, int lineIndex,
int valueIndex) {
if (selectedValue.getFirstIndex() == lineIndex && selectedValue.getSecondIndex() == valueIndex) {
int pointRadius = ChartUtils.dp2px(density, line.getPointRadius());
pointPaint.setColor(line.getDarkenColor());
drawPoint(canvas, line, pointValue, rawX, rawY, pointRadius + touchToleranceMargin);
if (line.hasLabels() || line.hasLabelsOnlyForSelected()) {
drawLabel(canvas, line, pointValue, rawX, rawY, pointRadius + labelOffset);
}
}
}
private void drawLabel(Canvas canvas, Line line, PointValue pointValue, float rawX, float rawY, float offset) {
final Rect contentRect = computator.getContentRectMinusAllMargins();
final int numChars = line.getFormatter().formatChartValue(labelBuffer, pointValue);
if (numChars == 0) {
// No need to draw empty label
return;
}
final float labelWidth = labelPaint.measureText(labelBuffer, labelBuffer.length - numChars, numChars);
final int labelHeight = Math.abs(fontMetrics.ascent);
float left = rawX - labelWidth / 2 - labelMargin;
float right = rawX + labelWidth / 2 + labelMargin;
float top;
float bottom;
if (pointValue.getY() >= baseValue) {
top = rawY - offset - labelHeight - labelMargin * 2;
bottom = rawY - offset;
} else {
top = rawY + offset;
bottom = rawY + offset + labelHeight + labelMargin * 2;
}
if (top < contentRect.top) {
top = rawY + offset;
bottom = rawY + offset + labelHeight + labelMargin * 2;
}
if (bottom > contentRect.bottom) {
top = rawY - offset - labelHeight - labelMargin * 2;
bottom = rawY - offset;
}
if (left < contentRect.left) {
left = rawX;
right = rawX + labelWidth + labelMargin * 2;
}
if (right > contentRect.right) {
left = rawX - labelWidth - labelMargin * 2;
right = rawX;
}
labelBackgroundRect.set(left, top, right, bottom);
drawLabelTextAndBackground(canvas, labelBuffer, labelBuffer.length - numChars, numChars,
line.getDarkenColor());
}
private void drawArea(Canvas canvas, Line line) {
final int lineSize = line.getValues().size();
if (lineSize < 2) {
//No point to draw area for one point or empty line.
return;
}
final Rect contentRect = computator.getContentRectMinusAllMargins();
final float baseRawValue = Math.min(contentRect.bottom, Math.max(computator.computeRawY(baseValue),
contentRect.top));
//That checks works only if the last point is the right most one.
final float left = Math.max(computator.computeRawX(line.getValues().get(0).getX()), contentRect.left);
final float right = Math.min(computator.computeRawX(line.getValues().get(lineSize - 1).getX()),
contentRect.right);
path.lineTo(right, baseRawValue);
path.lineTo(left, baseRawValue);
path.close();
linePaint.setStyle(Paint.Style.FILL);
linePaint.setAlpha(line.getAreaTransparency());
canvas.drawPath(path, linePaint);
linePaint.setStyle(Paint.Style.STROKE);
}
private boolean isInArea(float x, float y, float touchX, float touchY, float radius) {
float diffX = touchX - x;
float diffY = touchY - y;
return Math.pow(diffX, 2) + Math.pow(diffY, 2) <= 2 * Math.pow(radius, 2);
}
}