219437 - Javadocs of get/setAlpha(..) should specify range of value

3 files changed, 17 insertions, 6 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageData.java b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageData.java
index 0e45eb9cd0..4d4f7d88cf 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageData.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageData.java
@@ -581,6 +581,8 @@ public Object clone() {
 /**
  * Returns the alpha value at offset <code>x</code> in
  * scanline <code>y</code> in the receiver's alpha data.
+ * The alpha value is between 0 (transparent) and
+ * 255 (opaque).
  *
  * @param x the x coordinate of the pixel to get the alpha value of
  * @param y the y coordinate of the pixel to get the alpha value of
@@ -600,7 +602,9 @@ public int getAlpha(int x, int y) {
 /**
  * Returns <code>getWidth</code> alpha values starting at offset
  * <code>x</code> in scanline <code>y</code> in the receiver's alpha
- * data starting at <code>startIndex</code>.
+ * data starting at <code>startIndex</code>. The alpha values
+ * are unsigned, between <code>(byte)0</code> (transparent) and
+ * <code>(byte)255</code> (opaque).
  *
  * @param x the x position of the pixel to begin getting alpha values
  * @param y the y position of the pixel to begin getting alpha values
@@ -1151,6 +1155,8 @@ public ImageData scaledTo(int width, int height) {
 /**
  * Sets the alpha value at offset <code>x</code> in
  * scanline <code>y</code> in the receiver's alpha data.
+ * The alpha value must be between 0 (transparent)
+ * and 255 (opaque).
  *
  * @param x the x coordinate of the alpha value to set
  * @param y the y coordinate of the alpha value to set
@@ -1172,7 +1178,8 @@ public void setAlpha(int x, int y, int alpha) {
  * Sets the alpha values starting at offset <code>x</code> in
  * scanline <code>y</code> in the receiver's alpha data to the
  * values from the array <code>alphas</code> starting at
- * <code>startIndex</code>.
+ * <code>startIndex</code>. The alpha values must be between
+ * <code>(byte)0</code> (transparent) and <code>(byte)255</code> (opaque)
  *
  * @param x the x coordinate of the pixel to being setting the alpha values
  * @param y the y coordinate of the pixel to being setting the alpha values
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java
index 83ebd076ec..fb2035c748 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java
@@ -2961,7 +2961,8 @@ public boolean getAdvanced() {
 }
 
 /**
- * Returns the receiver's alpha value.
+ * Returns the receiver's alpha value. The alpha value
+ * is between 0 (transparent) and 255 (opaque).
  *
  * @return the alpha value
  *
@@ -3886,7 +3887,8 @@ public void setAntialias(int antialias) {
 }
 
 /**
- * Sets the receiver's alpha value.
+ * Sets the receiver's alpha value which must be
+ * between 0 (transparent) and 255 (opaque).
  * <p>
  * This operation requires the operating system's advanced
  * graphics subsystem which may not be available on some
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Shell.java b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Shell.java
index 5e0520fcbe..617fde5343 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Shell.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Shell.java
@@ -831,7 +831,8 @@ void forceResize () {
 }
 
 /**
- * Returns the receiver's alpha value.
+ * Returns the receiver's alpha value. The alpha value
+ * is between 0 (transparent) and 255 (opaque).
  *
  * @return the alpha value
  *
@@ -1352,7 +1353,8 @@ void setActiveControl (Control control) {
 }
 
 /**
- * Sets the receiver's alpha value.
+ * Sets the receiver's alpha value which must be
+ * between 0 (transparent) and 255 (opaque).
  * <p>
  * This operation requires the operating system's advanced
  * widgets subsystem which may not be available on some