meter.py

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