Dim secondary keys in every themes

Themes do not dim secondary keys the same way due to the "offset"
mechanism. Instead, use a ratio that is the same for every themes.

It's still possible to override this ratio per theme.

res/values/themes.xml

@@ -11,7 +11,7 @@
     <attr name="colorLabel" format="color"/>
     <attr name="colorLabelActivated" format="color"/>
     <attr name="colorLabelLocked" format="color"/>
-    <attr name="secondaryLightOffset" format="float"/>
+    <attr name="secondaryDimming" format="float"/>
     <!-- Corner labels -->
     <attr name="colorSubLabel" format="color"/>
     <!-- Borders -->
@@ -38,6 +38,7 @@
     <item name="keyBorderRadius">5dp</item>
     <item name="keyBorderWidth">0dp</item>
     <item name="keyBorderWidthActivated">0dp</item>
+    <item name="secondaryDimming">0.25</item>
     <item name="emoji_key_bg" type="color">?attr/emoji_button_bg</item>
     <item name="emoji_key_text" type="color">?attr/colorLabel</item>
   </style>
@@ -53,7 +54,6 @@
     <item name="colorLabelActivated">#3399ff</item>
     <item name="colorLabelLocked">#33cc33</item>
     <item name="colorSubLabel">#cccccc</item>
-    <item name="secondaryLightOffset">-0.2</item>
     <item name="emoji_button_bg" type="color">#202020</item>
     <item name="emoji_color" type="color">#ffffff</item>
   </style>
@@ -72,7 +72,6 @@
     <item name="colorLabelActivated">#0066cc</item>
     <item name="colorLabelLocked">#33cc33</item>
     <item name="colorSubLabel">#333333</item>
-    <item name="secondaryLightOffset">+0.3</item>
     <item name="emoji_button_bg">#dedede</item>
     <item name="emoji_color">#000000</item>
   </style>
@@ -91,7 +90,6 @@
     <item name="colorLabelActivated">#009dff</item>
     <item name="colorLabelLocked">#00ff26</item>
     <item name="colorSubLabel">#bbbbbb</item>
-    <item name="secondaryLightOffset">-0.25</item>
     <item name="keyBorderRadius">1dp</item>
     <item name="emoji_button_bg">#000000</item>
     <item name="emoji_color">#ffffff</item>
@@ -114,7 +112,6 @@
     <item name="colorLabelActivated">#0066cc</item>
     <item name="colorLabelLocked">#33cc33</item>
     <item name="colorSubLabel">#333333</item>
-    <item name="secondaryLightOffset">+0.35</item>
     <item name="emoji_button_bg">#ffffff</item>
     <item name="emoji_color">#000000</item>
   </style>
@@ -133,7 +130,6 @@
     <item name="colorLabelActivated">#000000</item>
     <item name="colorLabelLocked">#33cc33</item>
     <item name="colorSubLabel">#333333</item>
-    <item name="secondaryLightOffset">+0.35</item>
     <item name="emoji_button_bg">#ffffff</item>
     <item name="emoji_color">#000000</item>
   </style>
@@ -145,7 +141,6 @@
     <item name="colorLabel">#000000</item>
     <item name="colorLabelActivated">#ffffff</item>
     <item name="colorLabelLocked">#e65100</item>
-    <item name="secondaryLightOffset">0.1</item>
     <item name="colorSubLabel">#333333</item>
     <item name="keyBorderWidth">0.0dip</item>
     <item name="keyBorderWidthActivated">0.0dip</item>
@@ -164,7 +159,6 @@
     <item name="colorLabel">#000000</item>
     <item name="colorLabelActivated">#ffffff</item>
     <item name="colorLabelLocked">#64ffda</item>
-    <item name="secondaryLightOffset">0.0</item>
     <item name="colorSubLabel">#004d40</item>
     <item name="keyBorderWidth">0.0dip</item>
     <item name="keyBorderWidthActivated">0.0dip</item>

srcs/juloo.keyboard2/Theme.java

@@ -48,8 +48,8 @@ public class Theme
     activatedColor = s.getColor(R.styleable.keyboard_colorLabelActivated, 0);
     lockedColor = s.getColor(R.styleable.keyboard_colorLabelLocked, 0);
     subLabelColor = s.getColor(R.styleable.keyboard_colorSubLabel, 0);
-    float secondaryLightOffset = s.getFloat(R.styleable.keyboard_secondaryLightOffset, 1.f);
+    secondaryLabelColor = adjustLight(labelColor,
-    secondaryLabelColor = adjustLight(labelColor, secondaryLightOffset);
+        s.getFloat(R.styleable.keyboard_secondaryDimming, 0.25f));
     keyBorderRadius = s.getDimension(R.styleable.keyboard_keyBorderRadius, 0);
     keyBorderWidth = s.getDimension(R.styleable.keyboard_keyBorderWidth, 0);
     keyBorderWidthActivated = s.getDimension(R.styleable.keyboard_keyBorderWidthActivated, 0);
@@ -85,11 +85,13 @@ public class Theme
     return _indicationPaint;
   }
 
-  int adjustLight(int color, float offset)
+  /** Interpolate the 'value' component toward its opposite by 'alpha'. */
+  int adjustLight(int color, float alpha)
   {
     float[] hsv = new float[3];
     Color.colorToHSV(color, hsv);
-    hsv[2] += offset;
+    float v = hsv[2];
+    hsv[2] = alpha - (2 * alpha - 1) * v;
     return Color.HSVToColor(hsv);
   }