Separated color helpers from StateButtonStyle into a ColorHelperMixin class

blink/widgets/buttons.py

@@ -8,9 +8,8 @@ from PyQt4.QtCore import Qt, QLineF, QPointF, QRectF, QSize, QTimer, pyqtSignal,
 from PyQt4.QtGui  import QAction, QBrush, QColor, QCommonStyle, QLinearGradient, QIcon, QMenu, QPainter, QPainterPath, QPalette, QPen, QPixmap
 from PyQt4.QtGui  import QPolygonF, QPushButton, QStyle, QStyleOptionToolButton, QStylePainter, QToolButton
 
-from application.python.decorator import decorator, preserve_signature
 from blink.resources import Resources
-from blink.widgets.color import ColorScheme, ColorUtils
+from blink.widgets.color import ColorScheme, ColorUtils, ColorHelperMixin
 
 
 class ToolButton(QToolButton):
@@ -373,35 +372,7 @@ class SwitchViewButton(QPushButton):
         event.ignore()
 
 
-def color_key(instance, color):
-    return color.rgba()
-
-def color_ratio_key(instance, color, ratio):
-    return color.rgba() << 32 | int(ratio*512)
-
-def background_color_key(instance, background, color):
-    return background.rgba() << 32 | color.rgba()
-
-
-@decorator
-def cache_result(key_func):
-    def cache_results(function):
-        @preserve_signature(function)
-        def wrapper(*args, **kw):
-            key = key_func(*args, **kw)
-            try:
-                return wrapper.__cache__[key]
-            except KeyError:
-                return wrapper.__cache__.setdefault(key, function(*args, **kw))
-        wrapper.__cache__ = {}
-        return wrapper
-    return cache_results
-
-
-class StateButtonStyle(QCommonStyle):
-    _contrast = 0.3
-    _bgcontrast = min(1.0, 0.9*_contrast/0.7)
-
+class StateButtonStyle(QCommonStyle, ColorHelperMixin):
     _pixel_metrics = {QStyle.PM_MenuButtonIndicator: 11, QStyle.PM_DefaultFrameWidth: 3, QStyle.PM_ButtonMargin: 1, QStyle.PM_ButtonShiftHorizontal: 0, QStyle.PM_ButtonShiftVertical: 0,
                       QStyle.PM_ButtonIconSize: 32}
 
@@ -633,80 +604,6 @@ class StateButtonStyle(QCommonStyle):
             painter.setCompositionMode(QPainter.CompositionMode_SourceOver)
             painter.drawPixmap(pixmap_rect.topLeft(), pixmap)
 
-    # Color helpers
-
-    @cache_result(color_key)
-    def low_threshold(self, color):
-        darker = ColorScheme.shade(color, ColorScheme.MidShade, 0.5)
-        return ColorUtils.luma(darker) > ColorUtils.luma(color)
-
-    @cache_result(color_key)
-    def high_threshold(self, color):
-        lighter = ColorScheme.shade(color, ColorScheme.LightShade, 0.5)
-        return ColorUtils.luma(lighter) < ColorUtils.luma(color)
-
-    @cache_result(color_key)
-    def background_top_color(self, color):
-        if self.low_threshold(color):
-            return ColorScheme.shade(color, ColorScheme.MidlightShade, 0.0)
-        else:
-            other_luma = ColorUtils.luma(ColorScheme.shade(color, ColorScheme.LightShade, 0.0))
-            color_luma = ColorUtils.luma(color)
-            return ColorUtils.shade(color, (other_luma - color_luma) * self._bgcontrast)
-
-    @cache_result(color_key)
-    def background_bottom_color(self, color):
-        if self.low_threshold(color):
-            return ColorScheme.shade(color, ColorScheme.MidShade, 0.0)
-        else:
-            other_luma = ColorUtils.luma(ColorScheme.shade(color, ColorScheme.MidShade, 0.0))
-            color_luma = ColorUtils.luma(color)
-            return ColorUtils.shade(color, (other_luma - color_luma) * self._bgcontrast)
-
-    @cache_result(color_key)
-    def calc_light_color(self, color):
-        if self.high_threshold(color):
-            return color
-        else:
-            return ColorScheme.shade(color, ColorScheme.LightShade, self._contrast)
-
-    @cache_result(color_key)
-    def calc_dark_color(self, color):
-        if self.low_threshold(color):
-            return ColorUtils.mix(self.calc_light_color(color), color, 0.3 + 0.7 * self._contrast)
-        else:
-            return ColorScheme.shade(color, ColorScheme.MidShade, self._contrast)
-
-    @cache_result(color_key)
-    def calc_shadow_color(self, color):
-        if self.low_threshold(color):
-            shadow_color = ColorUtils.mix(Qt.black, color, color.alphaF())
-        else:
-            shadow_color = ColorScheme.shade(ColorUtils.mix(Qt.black, color, color.alphaF()), ColorScheme.ShadowShade, self._contrast)
-        shadow_color.setAlpha(color.alpha()) # make sure shadow color has the same alpha channel as the input
-        return shadow_color
-
-    @cache_result(color_ratio_key)
-    def background_color(self, color, ratio):
-        if ratio < 0.5:
-            return ColorUtils.mix(self.background_top_color(color), color, 2.0*ratio)
-        else:
-            return ColorUtils.mix(color, self.background_bottom_color(color), 2.0*ratio-1)
-
-    @cache_result(background_color_key)
-    def deco_color(self, background, color):
-        return ColorUtils.mix(background, color, 0.4 + 0.8*self._contrast)
-
-    def color_with_alpha(self, color, alpha):
-        color = QColor(color)
-        color.setAlpha(alpha)
-        return color
-
-    def alpha_color(self, color, alpha):
-        if 0.0 <= alpha < 1.0:
-            color.setAlphaF(alpha * color.alphaF())
-        return color
-
 
 class StateButton(QToolButton):
     default_color = QColor('#efedeb')

blink/widgets/color.py

 # Copyright (c) 2012 AG Projects. See LICENSE for details.
 #
 
-__all__ = ['ColorScheme', 'ColorUtils']
+__all__ = ['ColorScheme', 'ColorUtils', 'ColorHelperMixin']
 
-from PyQt4.QtGui import QColor
+from PyQt4.QtCore import Qt
+from PyQt4.QtGui  import QColor
 from application.python import limit
+from application.python.decorator import decorator, preserve_signature
 from math import fmod, isnan
 
 
@@ -199,3 +201,105 @@ class ColorUtils(object):
         return QColor.fromRgbF(r, g, b, a)
 
 
+def color_key(instance, color):
+    return color.rgba()
+
+def color_ratio_key(instance, color, ratio):
+    return color.rgba() << 32 | int(ratio*512)
+
+def background_color_key(instance, background, color):
+    return background.rgba() << 32 | color.rgba()
+
+
+@decorator
+def cache_result(key_func):
+    def cache_results(function):
+        @preserve_signature(function)
+        def wrapper(*args, **kw):
+            key = key_func(*args, **kw)
+            try:
+                return wrapper.__cache__[key]
+            except KeyError:
+                return wrapper.__cache__.setdefault(key, function(*args, **kw))
+        wrapper.__cache__ = {}
+        return wrapper
+    return cache_results
+
+
+class ColorHelperMixin(object):
+    _contrast = 0.3
+    _bgcontrast = min(1.0, 0.9*_contrast/0.7)
+
+    @cache_result(color_key)
+    def low_threshold(self, color):
+        darker = ColorScheme.shade(color, ColorScheme.MidShade, 0.5)
+        return ColorUtils.luma(darker) > ColorUtils.luma(color)
+
+    @cache_result(color_key)
+    def high_threshold(self, color):
+        lighter = ColorScheme.shade(color, ColorScheme.LightShade, 0.5)
+        return ColorUtils.luma(lighter) < ColorUtils.luma(color)
+
+    @cache_result(color_key)
+    def background_top_color(self, color):
+        if self.low_threshold(color):
+            return ColorScheme.shade(color, ColorScheme.MidlightShade, 0.0)
+        else:
+            other_luma = ColorUtils.luma(ColorScheme.shade(color, ColorScheme.LightShade, 0.0))
+            color_luma = ColorUtils.luma(color)
+            return ColorUtils.shade(color, (other_luma - color_luma) * self._bgcontrast)
+
+    @cache_result(color_key)
+    def background_bottom_color(self, color):
+        if self.low_threshold(color):
+            return ColorScheme.shade(color, ColorScheme.MidShade, 0.0)
+        else:
+            other_luma = ColorUtils.luma(ColorScheme.shade(color, ColorScheme.MidShade, 0.0))
+            color_luma = ColorUtils.luma(color)
+            return ColorUtils.shade(color, (other_luma - color_luma) * self._bgcontrast)
+
+    @cache_result(color_key)
+    def calc_light_color(self, color):
+        if self.high_threshold(color):
+            return color
+        else:
+            return ColorScheme.shade(color, ColorScheme.LightShade, self._contrast)
+
+    @cache_result(color_key)
+    def calc_dark_color(self, color):
+        if self.low_threshold(color):
+            return ColorUtils.mix(self.calc_light_color(color), color, 0.3 + 0.7 * self._contrast)
+        else:
+            return ColorScheme.shade(color, ColorScheme.MidShade, self._contrast)
+
+    @cache_result(color_key)
+    def calc_shadow_color(self, color):
+        if self.low_threshold(color):
+            shadow_color = ColorUtils.mix(Qt.black, color, color.alphaF())
+        else:
+            shadow_color = ColorScheme.shade(ColorUtils.mix(Qt.black, color, color.alphaF()), ColorScheme.ShadowShade, self._contrast)
+        shadow_color.setAlpha(color.alpha()) # make sure shadow color has the same alpha channel as the input
+        return shadow_color
+
+    @cache_result(color_ratio_key)
+    def background_color(self, color, ratio):
+        if ratio < 0.5:
+            return ColorUtils.mix(self.background_top_color(color), color, 2.0*ratio)
+        else:
+            return ColorUtils.mix(color, self.background_bottom_color(color), 2.0*ratio-1)
+
+    @cache_result(background_color_key)
+    def deco_color(self, background, color):
+        return ColorUtils.mix(background, color, 0.4 + 0.8*self._contrast)
+
+    def color_with_alpha(self, color, alpha):
+        color = QColor(color)
+        color.setAlpha(alpha)
+        return color
+
+    def alpha_color(self, color, alpha):
+        if 0.0 <= alpha < 1.0:
+            color.setAlphaF(alpha * color.alphaF())
+        return color
+
+