我正在创建一个支持透明度的 JPanel
,但是遇到了一个问题,即不确定如何将同一级别的透明度应用于添加到此面板的所有 Component
。 我目前的代码:
package de.uebertreiberman.project.swing;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import javax.swing.JPanel;
@SuppressWarnings("serial")
public class JTransparancyPanel extends JPanel {
float opacity = 1.0f;
/**Constructor for JTransparentPanel
*/
public JTransparancyPanel()
{
super();
this.setOpaque(false);
}
/**Getter for opacity value of panel
*
* @return float containing opacity value of frame (0-1)
*/
public float getOpacity()
{
return opacity;
}
/**Setter for opacity value of panel
*
* @param value as float for opacity of frame (0-1)
*/
public void setOpacity(float value)
{
opacity = value;
repaint();
}
/**Converts opacity value (0-1) to opacity color (0-255)
*
* @param opacity as float opacity value (0-1)
* @return integer containing converted opacity value (0-255)
*/
public static int getOpacityColor(float opacity)
{
return (int)(opacity * 255);
}
/**Converts opacity color (0-255) to opacity value (0-1)
*
* @param opacity as integer value (0-255)
* @return float containing converted opacity value (0-1)
*/
public static float getOpacityValue(int opacity)
{
//Returns more or less the correct, capped value
//Just ignore it, it works, leave it :D
return capFloat((3.9216f*opacity)/1000f, 0.0f, 1.0f);
}
/**Returns float capped between minimum and maximum value
*
* @param value as original value
* @param min as minimum cap value
* @param max as maximum cap value
* @return float containing capped value
*/
public static float capFloat(float value, float min, float max)
{
if(value < min) value = min;
else if(value > max) value = max;
return value;
}
/**Merges color and opacity to new color
*
* @param bg as color for old color, only RGB will be used from that
* @return color with RGB from bg and A from opacity of frame
*/
Color getTransparencyColor(Color bg)
{
return new Color(getOpacityValue(bg.getRed()), getOpacityValue(bg.getGreen()), getOpacityValue(bg.getBlue()), opacity);
}
@Override
public void paintComponent(Graphics g)
{
//Draw transparent background before painting other Components
g.setColor(getTransparencyColor(getBackground()));
Rectangle r = g.getClipBounds();
g.fillRect(r.x, r.y, r.width, r.height);
//Paint other components
super.paintComponent(g);
}
}
重要的部分基本上在最后,我覆盖了
paintComponent(Graphics g)
方法。我只是取
backgroundcolor
,应用透明度并设置它。现在我想让这个面板的所有子组件也变成透明的,但我不太确定最有效的方法是什么。
你有什么建议吗?
paint
/paintComponent
方法。没有任何东西可以阻止子组件肆意地填充其区域为纯色、不透明的颜色。可以尝试一些技巧,将子组件绘制到图像中,然后使用适当的不透明度绘制此图像。我会尝试一下,但可能有点棘手。 - Marco13Component[] components = jpanel.getComponents();
),遍历它们并使用getGraphics().setBackgroundColour()
设置它们的背景吗? - MrB