Example usage for com.google.gwt.widgetideas.graphics.client GWTCanvas saveContext

Introduction

In this page you can find the example usage for com.google.gwt.widgetideas.graphics.client GWTCanvas saveContext.

Prototype

public void saveContext() 

Source Link

Document

Saves the current context to the context stack.

Usage

From source file:org.utgenome.gwt.utgb.client.canvas.GWTGraphCanvas.java

License:Apache License

protected void drawWigGraph(GraphCanvas graphCanvas) {

    for (CompactWIGData data : graphCanvas.graphData) {

        // get graph color
        Color graphColor = new Color(DEFAULT_COLOR);
        if (style.color.isDefined()) {
            graphColor = new Color(style.color.get());
        } else if (data.getTrack().containsKey("color")) {
            String colorStr = data.getTrack().get("color");
            String c[] = colorStr.split(",");
            if (c.length == 3)
                graphColor = new Color(Integer.valueOf(c[0]), Integer.valueOf(c[1]), Integer.valueOf(c[2]));
        }/*from   w w  w  . ja  va  2 s .c o m*/

        // draw graph
        GWTCanvas canvas = graphCanvas.canvas;

        canvas.saveContext();
        canvas.setLineWidth(1.0f);
        canvas.setStrokeStyle(graphColor);

        //canvas.scale(viewWindow.convertToPixelLength(graphCanvas.window.getSequenceLength()) / (double) data.getPixelSize(), 1.0f);

        float y2 = getYPosition(0.0f);

        // draw data graph
        final boolean isReverse = graphCanvas.window.isReverseStrand();
        final int pixelWidth = data.getData().length;

        float min = style.autoScale ? autoScaledMinValue : style.minValue;
        float max = style.autoScale ? autoScaledMaxValue : style.maxValue;

        for (int i = 0; i < pixelWidth; ++i) {
            float value = data.getData()[i];
            float y1;
            if (value == 0.0f) {
                if (!style.drawZeroValue)
                    continue;
                else {
                    y1 = y2 + ((min < max) ? -0.5f : 0.5f);
                }
            } else {
                y1 = getYPosition(value);
            }

            int x = i;
            if (isReverse) {
                x = pixelWidth - x - 1;
            }

            canvas.saveContext();
            canvas.beginPath();
            canvas.translate(x + 0.5f, 0);
            canvas.moveTo(0, y1);
            canvas.lineTo(0, y2);
            canvas.stroke();
            canvas.restoreContext();
        }
        canvas.restoreContext();
    }

}

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