fix(holiday): 走势图折线数值标签回到贴近本点并加白描边

xyc

3 天以前 bdcd315656cf31777522ed1f7c9f72668d377903

 traffic-audit-server/src/main/java/com/trafficaudit/holiday/service/HolidayTrendChartService.java

@@ -74,7 +74,8 @@
    private static final Color MUTED_TEXT_COLOR = new Color(102, 102, 102);
    private static final double UNIT_LABEL_BAND = 58.0;
    private static final double RIGHT_LABEL_BAND = 74.0;
    private static final double ITEM_LABEL_GAP = 12.0;
    private static final double ITEM_LABEL_GAP = 10.0;
    private static final float HALO_OUTLINE_WIDTH = 4.0f;
    private static final Color ITEM_LABEL_COLOR = new Color(55, 55, 55);
    private static final Color[] SERIES_COLORS = {
            new Color(192, 80, 77),
@@ -841,7 +842,6 @@
        graphics.setFont(ITEM_LABEL_FONT);
        FontMetrics metrics = graphics.getFontMetrics();
        List<Rectangle2D> placedLabels = new ArrayList<>();
        List<Rectangle2D> markers = new ArrayList<>();
        if (unitLabel != null && !unitLabel.isEmpty()) {
            placedLabels.add(new Rectangle2D.Double(0.0, 0.0,
                    dataArea.getMinX() + 100.0, dataArea.getMinY() + 30.0));
@@ -849,13 +849,6 @@
        int itemCount = 0;
        for (int seriesIndex = 0; seriesIndex < dataset.getSeriesCount(); seriesIndex++) {
            itemCount = Math.max(itemCount, dataset.getItemCount(seriesIndex));
            for (int itemIndex = 0; itemIndex < dataset.getItemCount(seriesIndex); itemIndex++) {
                Point2D point = itemPoint(plot, dataset, seriesIndex, itemIndex, dataArea);
                if (point != null) {
                    markers.add(new Rectangle2D.Double(point.getX() - 9.0,
                            point.getY() - 9.0, 18.0, 18.0));
                }
            }
        }

        for (int itemIndex = 0; itemIndex < itemCount; itemIndex++) {
@@ -876,35 +869,95 @@
                    return Double.compare(first.getPoint().getY(), second.getPoint().getY());
                }
            });
            double previousBottom = Double.NEGATIVE_INFINITY;
            List<List<LineLabelCandidate>> candidateSets = new ArrayList<>();
            for (DayLabel label : labels) {
                int width = metrics.stringWidth(label.getText());
                int height = metrics.getHeight();
                double x = label.getPoint().getX() - width / 2.0;
                double top = Math.max(label.getPoint().getY() - ITEM_LABEL_GAP - height,
                        previousBottom + 3.0);
                Rectangle2D chosen = null;
                double bestPenalty = Double.MAX_VALUE;
                for (int step = 0; step <= 4; step++) {
                    Rectangle2D candidate = boundToDataArea(new Rectangle2D.Double(
                            x, top + step * (height + 4.0), width, height), dataArea);
                    if (candidate == null) continue;
                    double penalty = overlapArea(candidate, placedLabels) * 1000.0
                            + overlapArea(candidate, markers);
                    if (penalty < bestPenalty) {
                        bestPenalty = penalty;
                        chosen = candidate;
                    }
                    if (penalty <= 0.0) break;
                List<LineLabelCandidate> candidates = lineLabelCandidates(
                        label, metrics, dataArea);
                if (candidates.isEmpty()) {
                    candidateSets.clear();
                    break;
                }
                if (chosen == null) continue;
                candidateSets.add(candidates);
            }
            if (candidateSets.isEmpty()) continue;

            // Dynamic programming keeps each label near its own point while preserving
            // the same top-to-bottom order as the data points for that date.
            List<int[]> backPointers = new ArrayList<>();
            List<LineLabelCandidate> firstCandidates = candidateSets.get(0);
            double[] previousCosts = new double[firstCandidates.size()];
            for (int i = 0; i < firstCandidates.size(); i++) {
                previousCosts[i] = lineLabelCost(firstCandidates.get(i), labels.get(0),
                        labels, placedLabels);
            }

            for (int labelIndex = 1; labelIndex < candidateSets.size(); labelIndex++) {
                List<LineLabelCandidate> previousCandidates = candidateSets.get(labelIndex - 1);
                List<LineLabelCandidate> currentCandidates = candidateSets.get(labelIndex);
                double[] currentCosts = new double[currentCandidates.size()];
                Arrays.fill(currentCosts, Double.MAX_VALUE);
                int[] back = new int[currentCandidates.size()];
                Arrays.fill(back, -1);
                for (int currentIndex = 0; currentIndex < currentCandidates.size(); currentIndex++) {
                    LineLabelCandidate current = currentCandidates.get(currentIndex);
                    double currentCost = lineLabelCost(current, labels.get(labelIndex),
                            labels, placedLabels);
                    for (int previousIndex = 0; previousIndex < previousCandidates.size(); previousIndex++) {
                        if (previousCosts[previousIndex] == Double.MAX_VALUE) continue;
                        LineLabelCandidate previous = previousCandidates.get(previousIndex);
                        if (previous.getRectangle().getCenterY()
                                > current.getRectangle().getCenterY() + 0.1) {
                            continue;
                        }
                        double overlapPenalty = overlapArea(previous.getRectangle(),
                                Collections.singletonList(current.getRectangle())) * 1000000.0;
                        double cost = previousCosts[previousIndex] + currentCost + overlapPenalty;
                        if (cost < currentCosts[currentIndex]) {
                            currentCosts[currentIndex] = cost;
                            back[currentIndex] = previousIndex;
                        }
                    }
                }
                previousCosts = currentCosts;
                backPointers.add(back);
            }

            int bestLastIndex = -1;
            double bestCost = Double.MAX_VALUE;
            for (int i = 0; i < previousCosts.length; i++) {
                if (previousCosts[i] < bestCost) {
                    bestCost = previousCosts[i];
                    bestLastIndex = i;
                }
            }
            if (bestLastIndex < 0) continue;

            int[] chosenIndexes = new int[candidateSets.size()];
            chosenIndexes[chosenIndexes.length - 1] = bestLastIndex;
            for (int labelIndex = chosenIndexes.length - 2; labelIndex >= 0; labelIndex--) {
                int nextIndex = chosenIndexes[labelIndex + 1];
                chosenIndexes[labelIndex] = backPointers.get(labelIndex)[nextIndex];
            }
            for (int labelIndex = 0; labelIndex < chosenIndexes.length; labelIndex++) {
                DayLabel label = labels.get(labelIndex);
                Rectangle2D chosen = candidateSets.get(labelIndex)
                        .get(chosenIndexes[labelIndex]).getRectangle();
                drawLabelWithHalo(graphics, label.getText(), chosen, metrics,
                        seriesColor(label.getSeriesIndex()));
                placedLabels.add(new Rectangle2D.Double(chosen.getX() - 5.0, chosen.getY() - 5.0,
                        chosen.getWidth() + 10.0, chosen.getHeight() + 10.0));
                previousBottom = chosen.getMaxY();
                placedLabels.add(new Rectangle2D.Double(chosen.getX() - 4.0, chosen.getY() - 4.0,
                        chosen.getWidth() + 8.0, chosen.getHeight() + 8.0));
            }
        }
    }

    private static class LineLabelCandidate {
        private final Rectangle2D rectangle;

        private LineLabelCandidate(Rectangle2D rectangle) {
            this.rectangle = rectangle;
        }

        private Rectangle2D getRectangle() { return rectangle; }
    }

    private static class DayLabel {
@@ -937,10 +990,99 @@
        return new Point2D.Double(x, y);
    }

    private void addLabelCandidate(List<Rectangle2D> result, double x, double y,
                                   int width, int height, double dx, double dy) {
        result.add(new Rectangle2D.Double(x + dx - width / 2.0,
                y + dy - height / 2.0, width, height));
    private List<LineLabelCandidate> lineLabelCandidates(DayLabel label, FontMetrics metrics,
                                                         Rectangle2D dataArea) {
        List<LineLabelCandidate> result = new ArrayList<>();
        int width = metrics.stringWidth(label.getText());
        int height = metrics.getHeight();
        double x = label.getPoint().getX();
        double y = label.getPoint().getY();
        double horizontalOffset = ITEM_LABEL_GAP + width / 2.0;
        double farHorizontalOffset = horizontalOffset + 18.0;
        double verticalOffset = ITEM_LABEL_GAP + height / 2.0;
        double farVerticalOffset = verticalOffset + height + 6.0;
        addLabelCandidate(result, x, y, width, height, 0.0, -verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height, 0.0, verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height, horizontalOffset, 0.0, dataArea);
        addLabelCandidate(result, x, y, width, height, -horizontalOffset, 0.0, dataArea);
        addLabelCandidate(result, x, y, width, height, farHorizontalOffset, 0.0, dataArea);
        addLabelCandidate(result, x, y, width, height, -farHorizontalOffset, 0.0, dataArea);
        addLabelCandidate(result, x, y, width, height,
                horizontalOffset, -verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                horizontalOffset, verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -horizontalOffset, -verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -horizontalOffset, verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                farHorizontalOffset, -verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                farHorizontalOffset, verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -farHorizontalOffset, -verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -farHorizontalOffset, verticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height, 0.0, -farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height, 0.0, farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                horizontalOffset, -farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                horizontalOffset, farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -horizontalOffset, -farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -horizontalOffset, farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                farHorizontalOffset, -farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                farHorizontalOffset, farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -farHorizontalOffset, -farVerticalOffset, dataArea);
        addLabelCandidate(result, x, y, width, height,
                -farHorizontalOffset, farVerticalOffset, dataArea);
        return result;
    }

    private void addLabelCandidate(List<LineLabelCandidate> result, double x, double y,
                                   int width, int height, double dx, double dy,
                                   Rectangle2D dataArea) {
        Rectangle2D candidate = boundToDataArea(new Rectangle2D.Double(
                x + dx - width / 2.0, y + dy - height / 2.0, width, height), dataArea);
        if (candidate == null) return;
        for (LineLabelCandidate existing : result) {
            if (Math.abs(existing.getRectangle().getX() - candidate.getX()) < 0.5
                    && Math.abs(existing.getRectangle().getY() - candidate.getY()) < 0.5) {
                return;
            }
        }
        result.add(new LineLabelCandidate(candidate));
    }

    private double lineLabelCost(LineLabelCandidate candidate, DayLabel label,
                                List<DayLabel> sameDayLabels,
                                List<Rectangle2D> placedLabels) {
        Rectangle2D rectangle = candidate.getRectangle();
        double dx = rectangle.getCenterX() - label.getPoint().getX();
        double dy = rectangle.getCenterY() - label.getPoint().getY();
        double ownDistance = Math.sqrt(dx * dx + dy * dy);
        double cost = ownDistance * 10.0 + overlapArea(rectangle, placedLabels) * 10000.0;
        Rectangle2D ownMarker = new Rectangle2D.Double(label.getPoint().getX() - 9.0,
                label.getPoint().getY() - 9.0, 18.0, 18.0);
        if (rectangle.intersects(ownMarker)) cost += 3000.0;
        for (DayLabel other : sameDayLabels) {
            if (other == label) continue;
            double otherDx = rectangle.getCenterX() - other.getPoint().getX();
            double otherDy = rectangle.getCenterY() - other.getPoint().getY();
            double otherDistance = Math.sqrt(otherDx * otherDx + otherDy * otherDy);
            if (otherDistance < ownDistance - 1.0) {
                cost += (ownDistance - otherDistance) * 5000.0;
            }
            Rectangle2D otherMarker = new Rectangle2D.Double(other.getPoint().getX() - 9.0,
                    other.getPoint().getY() - 9.0, 18.0, 18.0);
            if (rectangle.intersects(otherMarker)) cost += 2000.0;
        }
        return cost;
    }

    private Rectangle2D boundToDataArea(Rectangle2D rectangle, Rectangle2D dataArea) {
@@ -979,14 +1121,18 @@
                                   FontMetrics metrics, Color color) {
        int x = (int) Math.round(rectangle.getX());
        int y = (int) Math.round(rectangle.getY() + metrics.getAscent());
        // A stroked white outline keeps the digit legible even when a line runs
        // underneath it, which lets labels stay right next to their own point.
        java.awt.font.TextLayout layout = new java.awt.font.TextLayout(
                text, graphics.getFont(), graphics.getFontRenderContext());
        java.awt.Shape outline = layout.getOutline(
                java.awt.geom.AffineTransform.getTranslateInstance(x, y));
        graphics.setColor(Color.WHITE);
        for (int dx = -1; dx <= 1; dx++) {
            for (int dy = -1; dy <= 1; dy++) {
                if (dx != 0 || dy != 0) graphics.drawString(text, x + dx, y + dy);
            }
        }
        graphics.setStroke(new BasicStroke(HALO_OUTLINE_WIDTH,
                BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
        graphics.draw(outline);
        graphics.setColor(color);
        graphics.drawString(text, x, y);
        graphics.fill(outline);
    }

    public static final List<String> DAY_LABELS = Arrays.asList(