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 logging
  19
  20 import cairo
  21 from gi.repository import Gtk
  22 from gi.repository import Gdk
  23 from gi.repository import GObject
  24
  25
  26 log = logging.getLogger(__name__)
  27
  28
  29 class MeterWidget(Gtk.DrawingArea):
  30     def __init__(self, scale):
  31         GObject.GObject.__init__(self)
  32
  33         self.scale = scale
  34
  35         self.connect("draw", self.draw)
  36         #self.connect("size-request", self.on_size_request)
  37         self.connect("size-allocate", self.on_size_allocate)
  38
  39         self.color_bg = Gdk.Color(0,0,0)
  40         self.color_value = None
  41         self.color_mark = Gdk.Color(int(65535 * 0.2), int(65535 * 0.2), int(65535 * 0.2))
  42         self.width = 0
  43         self.height = 0
  44         self.cache_surface = None
  45
  46     def get_preferred_width(self):
  47         log.debug('get_preferred_width called')
  48         return 2
  49
  50     def get_preferred_height(self):
  51         return 200
  52
  53     def set_color(self, color):
  54         self.color_value = color
  55         self.cache_surface = None
  56         self.invalidate_all()
  57
  58     def on_expose(self, widget, event):
  59         cairo_ctx = widget.window.cairo_create()
  60
  61         # set a clip region for the expose event
  62         cairo_ctx.rectangle(event.area.x, event.area.y, event.area.width, event.area.height)
  63         cairo_ctx.clip()
  64
  65         self.draw(cairo_ctx)
  66
  67         return False
  68
  69     def on_size_allocate(self, widget, allocation):
  70         self.width = float(allocation.width)
  71         self.height = float(allocation.height)
  72         self.font_size = 10
  73         self.cache_surface = None
  74
  75     def on_size_request(self, widget, requisition):
  76         log.debug("size-request, %u x %u", requisition.width, requisition.height)
  77         requisition.width = 20
  78         return
  79
  80     def invalidate_all(self):
  81         self.queue_draw_area(0, 0, int(self.width), int(self.height))
  82
  83     def draw_background(self, cairo_ctx):
  84         if not self.cache_surface:
  85             self.cache_surface = cairo.Surface.create_similar(
  86                             cairo_ctx.get_target(),
  87                             cairo.CONTENT_COLOR,
  88                             int(self.width),
  89                             int(self.height))
  90             cache_cairo_ctx = cairo.Context(self.cache_surface)
  91
  92             cache_cairo_ctx.set_source_rgba(0, 0, 0, 0)
  93             cache_cairo_ctx.rectangle(0, 0, self.width, self.height)
  94             cache_cairo_ctx.fill()
  95
  96             cache_cairo_ctx.set_source_rgba(0.2, 0.2, 0.2, 1)
  97             cache_cairo_ctx.select_font_face("Fixed")
  98             cache_cairo_ctx.set_font_size(self.font_size)
  99             glyph_width = self.font_size * 3 / 5 # avarage glyph ratio
 100             for mark in self.scale.get_marks():
 101                 mark_position = int(self.height * (1 - mark.scale))
 102                 cache_cairo_ctx.move_to(0, mark_position)
 103                 cache_cairo_ctx.line_to(self.width, mark_position)
 104                 cache_cairo_ctx.stroke()
 105                 x_correction = self.width / 2 - glyph_width * len(mark.text) / 2
 106                 cache_cairo_ctx.move_to(x_correction, mark_position - 2)
 107                 cache_cairo_ctx.show_text(mark.text)
 108         cairo_ctx.set_source_surface(self.cache_surface, 0, 0)
 109         cairo_ctx.paint()
 110
 111     def draw_value(self, cairo_ctx, value, x, width):
 112         if self.color_value is not None:
 113             cairo_ctx.set_source_rgb(self.color_value.red/65535.,
 114                     self.color_value.green/65535., self.color_value.blue/65535.)
 115         else:
 116             height = self.height
 117             gradient = cairo.LinearGradient(1, 1, width-1, height-1)
 118             gradient.add_color_stop_rgb(0, 1, 0, 0)
 119             gradient.add_color_stop_rgb(0.2, 1, 1, 0)
 120             gradient.add_color_stop_rgb(1, 0, 1, 0)
 121             cairo_ctx.set_source(gradient)
 122         cairo_ctx.rectangle(x, self.height * (1 - value), width, self.height * value)
 123         cairo_ctx.fill()
 124
 125     def set_scale(self, scale):
 126         self.scale = scale
 127         self.cache_surface = None
 128         self.invalidate_all()
 129
 130
 131 class MonoMeterWidget(MeterWidget):
 132     def __init__(self, scale):
 133         MeterWidget.__init__(self, scale)
 134         self.value = 0.0
 135         self.raw_value = 0.0
 136
 137     def draw(self, widget, cairo_ctx):
 138         self.draw_background(cairo_ctx)
 139         self.draw_value(cairo_ctx, self.value, self.width/4.0, self.width/2.0)
 140
 141     def set_value(self, value):
 142         if value != self.raw_value:
 143             self.raw_value = value
 144             self.value = self.scale.db_to_scale(value)
 145             self.invalidate_all()
 146         if value == self.raw_value:
 147             return
 148         self.raw_value = value
 149         old_value = self.value
 150         self.value = self.scale.db_to_scale(value)
 151         if (abs(old_value-self.value) * self.height) > 1:
 152             self.invalidate_all()
 153
 154
 155 class StereoMeterWidget(MeterWidget):
 156     def __init__(self, scale):
 157         MeterWidget.__init__(self, scale)
 158         self.left = 0.0
 159         self.right = 0.0
 160
 161         self.raw_left = 0.0
 162         self.raw_right = 0.0
 163
 164     def draw(self, widget, cairo_ctx):
 165         self.draw_background(cairo_ctx)
 166         self.draw_value(cairo_ctx, self.left, self.width/5.0, self.width/5.0)
 167         self.draw_value(cairo_ctx, self.right, self.width/5.0 * 3.0, self.width/5.0)
 168
 169     def set_values(self, left, right):
 170         if left == self.raw_left and right == self.raw_right:
 171             return
 172         self.raw_left = left
 173         self.raw_right = right
 174         old_left = self.left
 175         old_right = self.right
 176         self.left = self.scale.db_to_scale(left)
 177         self.right = self.scale.db_to_scale(right)
 178         if (abs(old_left-self.left) * self.height) > 0.01 or (abs(old_right-self.right) * self.height) > 0.01:
 179             self.invalidate_all()