Improved modern light theme

First attempt to use HSV model - no need to dance with RGB equalizing.
Two utility functions are added to complement missing QColor functionality.

Strange border with audio jack ports in very begining seems to be accedental,
so trying to improve original color scheme. Background is light grey (some least
color contrast would be great, even with border). Unselected port text is colored.

src/patchcanvas_theme.py

@@ -25,6 +25,23 @@ from PyQt4.QtGui import QColor, QFont, QFontMetrics, QPen, QPixmap
 # ------------------------------------------------------------------------------------------------------------
 # patchcanvas-theme.cpp
 
+# Utilities
+## hsvAdjusted() - returns color with selectively rewrote HSV parameters
+def hsvAdjusted(color, hue = -1, saturation = -1, value = -1, alpha = -1):
+    if hue == -1:        hue = color.hue()
+    if saturation == -1: saturation = color.saturation()
+    if value == -1:      value = color.value()
+    if alpha == -1:      alpha = color.alpha()
+    return QColor.fromHsv(hue, saturation, value, alpha)
+
+## hsvAdjusted() variant for relative changes
+def hsvAdjustedRel(color, hue = 0, saturation = 0, value = 0, alpha = 0):
+    return QColor.fromHsv(
+      color.hue()+hue,
+      color.saturation()+saturation,
+      color.value()+value,
+      color.alpha()+alpha)
+
 class Theme(object):
     # enum PortType
     THEME_PORT_SQUARE  = 0
@@ -243,8 +260,8 @@ class Theme(object):
             # Boxes
             self.box_pen = QPen(QColor(176, 177, 178), 1, Qt.SolidLine)
             self.box_pen_sel = QPen(QColor(1, 2, 3), 2, Qt.DashLine)
-            self.box_bg_1 = QColor(250, 250, 250)
-            self.box_bg_2 = QColor(200, 200, 200)
+            self.box_bg_1 = QColor(220, 220, 220)
+            self.box_bg_2 = self.box_bg_1.darker(120)
             self.box_shadow = QColor(1, 1, 1, 100)
             self.box_header_pixmap  = None
             self.box_header_height  = 24
@@ -254,51 +271,61 @@ class Theme(object):
             self.box_text = QPen(QColor(1, 1, 1), 0)
             self.box_text_sel  = self.box_text
             self.box_font_name = "Ubuntu"
-            self.box_font_size = 11
+            self.box_font_size = 10
             self.box_font_state = QFont.Bold
 
             self.box_bg_type  = self.THEME_BG_GRADIENT
             self.box_use_icon = True
 
             # Ports
-            self.port_text = QPen(QColor(30, 30, 30, 180), 1)
+            self.port_text = QPen(QColor(255, 255, 255, 220), 1)
             self.port_bg_pixmap = None
             self.port_font_name = "Ubuntu"
-            self.port_font_size = 10
+            self.port_font_size = 9
             self.port_font_state = QFont.Bold
             self.port_mode = self.THEME_PORT_POLYGON
 
-            self.port_audio_jack_pen = QPen(QColor(50, 50, 150), 1)
-            self.port_audio_jack_pen_sel = QPen(QColor(103 + 136, 190 + 130, 226 + 130), 1)
-            self.port_midi_jack_pen = QPen(QColor(150, 50, 50), 1)
-            self.port_midi_jack_pen_sel = QPen(QColor(90 + 30, 44 + 30, 42 + 30), 1)
-            self.port_midi_a2j_pen = QPen(QColor(100, 50, 30), 1)
-            self.port_midi_a2j_pen_sel = QPen(QColor(137 + 30, 76 + 30, 43 + 30), 1)
-            self.port_midi_alsa_pen = QPen(QColor(45, 150, 50), 1)
-            self.port_midi_alsa_pen_sel = QPen(QColor(93 + 30, 141 + 30, 46 + 30), 1)
-
-            self.port_audio_jack_bg = QColor(150, 150, 255)
-            self.port_audio_jack_bg_sel = QColor(135 + 150, 161 + 150, 199 + 150)
-            self.port_midi_jack_bg = QColor(255, 150, 160)
-            self.port_midi_jack_bg_sel = QColor(90 + 30, 15 + 50, 16 + 50)
-            self.port_midi_a2j_bg = QColor(200, 135, 100)
-            self.port_midi_a2j_bg_sel = QColor(101 + 50, 47 + 50, 16 + 50)
-            self.port_midi_alsa_bg = QColor(160, 255, 150)
-            self.port_midi_alsa_bg_sel = QColor(64 + 50, 112 + 50, 18 + 50)
-
-            self.port_audio_jack_text = self.port_text
+            # Port colors
+            port_audio_jack_color = QColor.fromHsv(240, 214, 181)
+            port_midi_jack_color = QColor.fromHsv(0, 214, 130)
+            port_midi_a2j_color = QColor.fromHsv(22, 214, 102)
+            port_midi_alsa_color = QColor.fromHsv(91, 214, 112)
+
+            port_lineW = 1
+            port_pen_shade = 130
+            self.port_audio_jack_pen = QPen(port_audio_jack_color.darker(port_pen_shade), port_lineW)
+            self.port_midi_jack_pen = QPen(port_midi_jack_color.darker(port_pen_shade), port_lineW)
+            self.port_midi_a2j_pen = QPen(port_midi_a2j_color.darker(port_pen_shade), port_lineW)
+            self.port_midi_alsa_pen = QPen(port_midi_alsa_color.darker(port_pen_shade), port_lineW)
+            port_selW = 1.5
+            self.port_audio_jack_pen_sel = QPen(port_audio_jack_color.lighter(port_pen_shade), port_selW)
+            self.port_midi_jack_pen_sel = QPen(port_midi_jack_color.lighter(port_pen_shade), port_selW)
+            self.port_midi_a2j_pen_sel = QPen(port_midi_a2j_color.lighter(port_pen_shade), port_selW)
+            self.port_midi_alsa_pen_sel = QPen(port_midi_alsa_color.lighter(port_pen_shade), port_selW)
+
+            port_bg_shade = 170
+            self.port_audio_jack_bg = port_audio_jack_color
+            self.port_midi_jack_bg = port_midi_jack_color
+            self.port_midi_a2j_bg = port_midi_a2j_color
+            self.port_midi_alsa_bg = port_midi_alsa_color
+            self.port_audio_jack_bg_sel = hsvAdjustedRel(self.port_audio_jack_bg, saturation = -80).lighter(130)
+            self.port_midi_jack_bg_sel = hsvAdjustedRel(self.port_midi_jack_bg, saturation = -80).lighter(130)
+            self.port_midi_a2j_bg_sel = hsvAdjustedRel(self.port_midi_a2j_bg, saturation = -80).lighter(130)
+            self.port_midi_alsa_bg_sel = hsvAdjustedRel(self.port_midi_alsa_bg, saturation = -80).lighter(130)
+
+            self.port_audio_jack_text = QPen(hsvAdjustedRel(port_audio_jack_color, hue = -30, saturation = -70, value = 70), 1)
+            self.port_midi_jack_text = QPen(hsvAdjustedRel(port_midi_jack_color, hue = 10, saturation = -70, value = 70), 1)
+            self.port_midi_a2j_text = QPen(hsvAdjustedRel(port_midi_a2j_color, hue = 8, saturation = -70, value = 70), 1)
+            self.port_midi_alsa_text = QPen(hsvAdjustedRel(port_midi_alsa_color, hue = -8, saturation = -70, value = 70), 1)
             self.port_audio_jack_text_sel = self.port_text
-            self.port_midi_jack_text = self.port_text
             self.port_midi_jack_text_sel = self.port_text
-            self.port_midi_a2j_text = self.port_text
             self.port_midi_a2j_text_sel = self.port_text
-            self.port_midi_alsa_text = self.port_text
             self.port_midi_alsa_text_sel = self.port_text
 
-            self.port_text_padding = 0
+            self.port_text_padding = 0.5
             self.port_offset   = 0
-            self.port_spacing  = 3
-            self.port_spacingT = 2
+            self.port_spacing  = 2
+            self.port_spacingT = 1
             self.port_rounding = 0.0
 
             # To not scale some line widths