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