/** Draws this axis. */
@Override
public void paint(final int newPaintEventId) {
// guard against redundant paints
if (previousPaintEventId != newPaintEventId) {
previousPaintEventId = newPaintEventId;
final Canvas canvas = getDrawingCanvas();
if (canvas == null) {
return;
}
canvas.getSurface().clear();
// Pick the color to use, based on highlighting status
if (isHighlighted()) {
canvas.setStrokeStyle(HIGHLIGHTED_COLOR);
} else {
canvas.setStrokeStyle(NORMAL_COLOR);
}
final double x = project2D(INITIAL_MIN).getX();
final double width = getWidth();
// Now figure out where the line should go, drawing ticks
// as we go along
double topValue = PHOTO_CENTER_LOCATION + PHOTO_HEIGHT / 2.0;
double bottomValue = PHOTO_CENTER_LOCATION - PHOTO_HEIGHT / 2.0;
// Don't draw anything at all if the line is out of bounds
if (bottomValue > getMax() || topValue < getMin()) {
return;
}
// Allow ourselves to begin drawing
canvas.beginPath();
if (topValue > getMax()) {
topValue = getMax();
} else {
drawTick(canvas, topValue, x, width);
}
if (bottomValue < getMin()) {
bottomValue = getMin();
} else {
drawTick(canvas, bottomValue, x, width);
}
// Get the values in pixels for where the line should go
final double topY = projectY(topValue);
final double bottomY = projectY(bottomValue);
// Now draw the vertical line
canvas.getRenderer().drawLineSegment(x, topY, x, bottomY);
// Actually render all our ticks and lines on the canvas
canvas.stroke();
// Clean up after ourselves
canvas.setStrokeStyle(Canvas.DEFAULT_COLOR);
}
}
