meter.py

   1 # This file is part of jack_mixer
   2 #
   3 # Copyright (C) 2006 Nedko Arnaudov <nedko@arnaudov.name>
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; version 2 of the License
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program; if not, write to the Free Software
  16 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17
  18 import gtk
  19 import cairo
  20
  21 class MeterWidget(gtk.DrawingArea):
  22     def __init__(self, scale):
  23         gtk.DrawingArea.__init__(self)
  24
  25         self.scale = scale
  26
  27         self.connect("expose-event", self.on_expose)
  28         self.connect("size-request", self.on_size_request)
  29         self.connect("size_allocate", self.on_size_allocate)
  30
  31         self.color_bg = gtk.gdk.Color(0,0,0)
  32         self.color_value = None
  33         self.color_mark = gtk.gdk.Color(int(65535 * 0.2), int(65535 * 0.2), int(65535 * 0.2))
  34         self.width = 0
  35         self.height = 0
  36         self.cache_surface = None
  37
  38     def set_color(self, color):
  39         self.color_value = color
  40         self.cache_surface = None
  41         self.invalidate_all()
  42
  43     def on_expose(self, widget, event):
  44         cairo_ctx = widget.window.cairo_create()
  45
  46         # set a clip region for the expose event
  47         cairo_ctx.rectangle(event.area.x, event.area.y, event.area.width, event.area.height)
  48         cairo_ctx.clip()
  49
  50         self.draw(cairo_ctx)
  51
  52         return False
  53
  54     def on_size_allocate(self, widget, allocation):
  55         #print allocation.x, allocation.y, allocation.width, allocation.height
  56         self.width = float(allocation.width)
  57         self.height = float(allocation.height)
  58         self.font_size = 10
  59         self.cache_surface = None
  60
  61     def on_size_request(self, widget, requisition):
  62         #print "size-request, %u x %u" % (requisition.width, requisition.height)
  63         requisition.width = 20
  64         return
  65
  66     def invalidate_all(self):
  67         self.queue_draw_area(0, 0, int(self.width), int(self.height))
  68
  69     def draw_background(self, cairo_ctx):
  70         if not self.cache_surface:
  71             self.cache_surface = cairo.Surface.create_similar(
  72                             cairo_ctx.get_target(),
  73                             cairo.CONTENT_COLOR,
  74                             int(self.width),
  75                             int(self.height))
  76             cache_cairo_ctx = cairo.Context(self.cache_surface)
  77
  78             cache_cairo_ctx.set_source_rgba(0, 0, 0, 0)
  79             cache_cairo_ctx.rectangle(0, 0, self.width, self.height)
  80             cache_cairo_ctx.fill()
  81
  82             cache_cairo_ctx.set_source_rgba(0.2, 0.2, 0.2, 1)
  83             cache_cairo_ctx.select_font_face("Fixed")
  84             cache_cairo_ctx.set_font_size(self.font_size)
  85             glyph_width = self.font_size * 3 / 5 # avarage glyph ratio
  86             for mark in self.scale.get_marks():
  87                 mark_position = int(self.height * (1 - mark.scale))
  88                 cache_cairo_ctx.move_to(0, mark_position)
  89                 cache_cairo_ctx.line_to(self.width, mark_position)
  90                 cache_cairo_ctx.stroke()
  91                 x_correction = self.width / 2 - glyph_width * len(mark.text) / 2
  92                 cache_cairo_ctx.move_to(x_correction, mark_position - 2)
  93                 cache_cairo_ctx.show_text(mark.text)
  94         cairo_ctx.set_source_surface(self.cache_surface, 0, 0)
  95         cairo_ctx.paint()
  96
  97     def draw_value(self, cairo_ctx, value, x, width):
  98         if self.color_value is not None:
  99             cairo_ctx.set_source_color(self.color_value)
 100         else:
 101             height = self.allocation.height
 102             gradient = cairo.LinearGradient(1, 1, width-1, height-1)
 103             gradient.add_color_stop_rgb(0, 1, 0, 0)
 104             gradient.add_color_stop_rgb(0.2, 1, 1, 0)
 105             gradient.add_color_stop_rgb(1, 0, 1, 0)
 106             cairo_ctx.set_source(gradient)
 107         cairo_ctx.rectangle(x, self.height * (1 - value), width, self.height * value)
 108         cairo_ctx.fill()
 109
 110     def set_scale(self, scale):
 111         self.scale = scale
 112         self.cache_surface = None
 113         self.invalidate_all()
 114
 115 class MonoMeterWidget(MeterWidget):
 116     def __init__(self, scale):
 117         MeterWidget.__init__(self, scale)
 118         self.value = 0.0
 119         self.raw_value = 0.0
 120
 121     def draw(self, cairo_ctx):
 122         self.draw_background(cairo_ctx)
 123         self.draw_value(cairo_ctx, self.value, self.width/4.0, self.width/2.0)
 124
 125     def set_value(self, value):
 126         if value != self.raw_value:
 127             self.raw_value = value
 128             self.value = self.scale.db_to_scale(value)
 129             self.invalidate_all()
 130         if value == self.raw_value:
 131             return
 132         self.raw_value = value
 133         old_value = self.value
 134         self.value = self.scale.db_to_scale(value)
 135         if (abs(old_value-self.value) * self.height) > 1:
 136             self.invalidate_all()
 137
 138 class StereoMeterWidget(MeterWidget):
 139     def __init__(self, scale):
 140         MeterWidget.__init__(self, scale)
 141         self.left = 0.0
 142         self.right = 0.0
 143
 144         self.raw_left = 0.0
 145         self.raw_right = 0.0
 146
 147     def draw(self, cairo_ctx):
 148         self.draw_background(cairo_ctx)
 149         self.draw_value(cairo_ctx, self.left, self.width/5.0, self.width/5.0)
 150         self.draw_value(cairo_ctx, self.right, self.width/5.0 * 3.0, self.width/5.0)
 151
 152     def set_values(self, left, right):
 153         if left == self.raw_left and right == self.raw_right:
 154             return
 155         self.raw_left = left
 156         self.raw_right = right
 157         old_left = self.left
 158         old_right = self.right
 159         self.left = self.scale.db_to_scale(left)
 160         self.right = self.scale.db_to_scale(right)
 161         if (abs(old_left-self.left) * self.height) > 1 or (abs(old_right-self.right) * self.height) > 1:
 162             self.invalidate_all()