Example usage for com.google.gwt.canvas.dom.client ImageData getRedAt

Introduction

In this page you can find the example usage for com.google.gwt.canvas.dom.client ImageData getRedAt.

Prototype

public final int getRedAt(int x, int y) 

Source Link

Document

Returns the red value at position (x,y).

Usage

From source file:jetbrains.jetpad.projectional.domUtil.TextMetricsCalculator.java

License:Apache License

private static int measureHeight(Font font, String text) {
    Canvas canvas = canvas();/*from  w w  w  .ja v a 2  s. c om*/
    Context2d ctx = canvas.getContext2d();

    ctx.setFont(getFontString(font));
    ctx.setFillStyle("rgb(255, 0, 0)");

    int width = (int) ctx.measureText(text).getWidth();
    int canvasHeight = font.getSize() * 2;
    canvas.setHeight(canvasHeight + "px");
    canvas.setHeight(font.getSize() * 2 + "px");
    canvas.setWidth(width + "px");

    ctx.fillText(text, 0, font.getSize());
    ImageData data = ctx.getImageData(0, 0, width, canvasHeight);
    int firstY = canvasHeight - 1;
    int lastY = 0;
    for (int x = 0; x < width; x++) {
        for (int y = 0; y < canvasHeight; y++) {
            int red = data.getRedAt(x, y);
            if (red != 0) {
                if (firstY > y) {
                    firstY = y;
                }
                if (lastY < y) {
                    lastY = y;
                }
            }
        }
    }
    return lastY - firstY;
}

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From source file:nl.mpi.tg.eg.experiment.client.view.ColourPickerCanvasView.java

License:Open Source License

private void setColour(int x, int y, Canvas targetCanvas, VerticalPanel targetPanel) {
    x = (x >= targetCanvas.getCoordinateSpaceWidth()) ? targetCanvas.getCoordinateSpaceWidth() - 1 : x;
    y = (y >= targetCanvas.getCoordinateSpaceHeight()) ? targetCanvas.getCoordinateSpaceHeight() - 1 : y;
    final ImageData imageData = targetCanvas.getContext2d().getImageData(x, y, 1, 1);
    final int blue = imageData.getBlueAt(0, 0);
    final int green = imageData.getGreenAt(0, 0);
    final int red = imageData.getRedAt(0, 0);
    if (targetPanel.equals(selectedColourPanel)) {
        selectedColourData = new ColourData(red, green, blue);
    }//www . ja v a  2  s .c  om
    targetPanel.getElement().setAttribute("style", "background:rgb(" + red + "," + green + "," + blue + ")");
}

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From source file:nl.mpi.tg.eg.experiment.client.view.ColourPickerCanvasView.java

License:Open Source License

private void setHue(int x, int y, Canvas targetCanvas) {
    x = (x >= targetCanvas.getCoordinateSpaceWidth()) ? targetCanvas.getCoordinateSpaceWidth() - 1 : x;
    y = (y >= targetCanvas.getCoordinateSpaceHeight()) ? targetCanvas.getCoordinateSpaceHeight() - 1 : y;
    final ImageData imageData = targetCanvas.getContext2d().getImageData(x, y, 1, 1);
    final int blue = imageData.getBlueAt(0, 0);
    final int green = imageData.getGreenAt(0, 0);
    final int red = imageData.getRedAt(0, 0);
    setHue(red, green, blue);//from www . ja v a 2 s  .  c  om
}

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