Add support for transarent png images

src/color.rs

@@ -6,19 +6,20 @@ pub struct Color {
     r: u8,
     g: u8,
     b: u8,
+    a: u8,
 }
 
 impl Color {
     /// Constructor.
     ///
     /// The color channels must be between 0 and 255.
-    pub fn from(r: u8, g: u8, b: u8) -> Color {
-        Color { r, g, b }
+    pub fn from(r: u8, g: u8, b: u8, a: u8) -> Color {
+        Color { r, g, b, a}
     }
 
     /// Get a hexadecimal representation of the color,
     /// such as `FFFFFF` for white and `FF0000` for red.
     pub fn as_hex(self) -> String {
-        format!("{:02X}{:02X}{:02X}", self.r, self.g, self.b)
+        format!("{:02X}{:02X}{:02X}{:02X}", self.r, self.g, self.b, self.a)
     }
 }

src/painter/painter.rs

@@ -51,7 +51,7 @@ impl Painter {
         }
 
         // Get an RGB image
-        let image = self.image.as_mut().unwrap().to_rgb();
+        let image = self.image.as_mut().unwrap().to_rgba();
 
         // Loop through all the pixels, and set their color
         for x in 0..self.area.w {
@@ -68,7 +68,8 @@ impl Painter {
                 let channels = pixel.channels();
 
                 // Define the color
-                let color = Color::from(channels[0], channels[1], channels[2]);
+                let color = Color::from(channels[0], channels[1], channels[2], channels[3]);
+
 
                 // Set the pixel
                 if let Some(client) = &mut self.client {