ColorGradientpublic class ColorGradient extends Applet | An applet that demonstrates the Color class |
| Fields Summary |
|---|
| Color | startColor | | Color | endColor | | Font | bigFont |
| Methods Summary |
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| public void | fillGradient(java.awt.Component c, java.awt.Graphics g, java.awt.Color start, java.awt.Color end)Draw a color gradient from the top of the specified component to the
bottom. Start with the start color and change smoothly to the end
Rectangle bounds = this.getBounds(); // How big is the component?
// Get the red, green, and blue components of the start and end
// colors as floats between 0.0 and 1.0. Note that the Color class
// also works with int values between 0 and 255
float r1 = start.getRed()/255.0f;
float g1 = start.getGreen()/255.0f;
float b1 = start.getBlue()/255.0f;
float r2 = end.getRed()/255.0f;
float g2 = end.getGreen()/255.0f;
float b2 = end.getBlue()/255.0f;
// Figure out how much each component should change at each y value
float dr = (r2-r1)/bounds.height;
float dg = (g2-g1)/bounds.height;
float db = (b2-b1)/bounds.height;
// Now loop once for each row of pixels in the component
for(int y = 0; y < bounds.height; y++) {
g.setColor(new Color(r1, g1, b1)); // Set the color of the row
g.drawLine(0, y, bounds.width-1, y); // Draw the row
r1 += dr; g1 += dg; b1 += db; // Increment color components
}
| | public void | init()Get the gradient start and end colors as applet parameter values, and
parse them using Color.decode(). If they are malformed, use white.
try {
startColor = Color.decode(getParameter("startColor"));
endColor = Color.decode(getParameter("endColor"));
}
catch (NumberFormatException e) {
startColor = endColor = Color.white;
}
bigFont = new Font("Helvetica", Font.BOLD, 72);
| | public void | paint(java.awt.Graphics g)Draw the applet. The interesting code is in fillGradient() below
fillGradient(this, g, startColor, endColor); // display the gradient
g.setFont(bigFont); // set a font
g.setColor(new Color(100, 100, 200)); // light blue
g.drawString("Colors!", 100, 100); // draw something interesting
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