src/gpodder/draw.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # gPodder - A media aggregator and podcast client
   4 # Copyright (c) 2005-2009 Thomas Perl and the gPodder Team
   5 #
   6 # gPodder is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # gPodder 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, see <http://www.gnu.org/licenses/>.
  18 #
  19
  20
  21 #
  22 #  draw.py -- Draw routines for gPodder-specific graphics
  23 #  Thomas Perl <thp@perli.net>, 2007-11-25
  24 #
  25
  26
  27 import gtk
  28 import pango
  29 import cairo
  30 import StringIO
  31
  32
  33 class TextExtents(object):
  34     def __init__(self, ctx, text):
  35         tuple = ctx.text_extents(text)
  36         (self.x_bearing, self.y_bearing, self.width, self.height, self.x_advance, self.y_advance) = tuple
  37
  38
  39 RRECT_LEFT_SIDE = 1
  40 RRECT_RIGHT_SIDE = 2
  41
  42 def draw_rounded_rectangle(ctx, x, y, w, h, r=10, left_side_width = None, sides_to_draw=0, close=False):
  43     if left_side_width is None:
  44         left_side_width = flw/2
  45
  46     x = int(x)
  47     offset = 0
  48     if close: offset = 0.5
  49
  50     if sides_to_draw & RRECT_LEFT_SIDE:
  51         ctx.move_to(x+int(left_side_width)-offset, y+h)
  52         ctx.line_to(x+r, y+h)
  53         ctx.curve_to(x, y+h, x, y+h, x, y+h-r)
  54         ctx.line_to(x, y+r)
  55         ctx.curve_to(x, y, x, y, x+r, y)
  56         ctx.line_to(x+int(left_side_width)-offset, y)
  57         if close:
  58             ctx.line_to(x+int(left_side_width)-offset, y+h)
  59
  60     if sides_to_draw & RRECT_RIGHT_SIDE:
  61         ctx.move_to(x+int(left_side_width)+offset, y)
  62         ctx.line_to(x+w-r, y)
  63         ctx.curve_to(x+w, y, x+w, y, x+w, y+r)
  64         ctx.line_to(x+w, y+h-r)
  65         ctx.curve_to(x+w, y+h, x+w, y+h, x+w-r, y+h)
  66         ctx.line_to(x+int(left_side_width)+offset, y+h)
  67         if close:
  68             ctx.line_to(x+int(left_side_width)+offset, y)
  69
  70
  71 def draw_text_pill(left_text, right_text, x=0, y=0, border=4, radius=14):
  72     # Create temporary context to calculate the text size
  73     ctx = cairo.Context(cairo.ImageSurface(cairo.FORMAT_ARGB32, 1, 1))
  74
  75     # Use GTK+ style of a normal Button
  76     widget = gtk.ProgressBar()
  77     style = widget.rc_get_style()
  78
  79     x_border = int(border*1.2)
  80
  81     font_desc = style.font_desc
  82     font_size = float(1.15*font_desc.get_size())/float(pango.SCALE)
  83     font_name = font_desc.get_family()
  84
  85     ctx.set_font_size(font_size)
  86     ctx.select_font_face(font_name, cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
  87
  88     left_text_e = TextExtents(ctx, left_text)
  89     right_text_e = TextExtents(ctx, right_text)
  90     text_height = max(left_text_e.height, right_text_e.height)
  91
  92     image_height = int(y+text_height+border*2)
  93     image_width = int(x+left_text_e.width+right_text_e.width+x_border*4)
  94     surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, image_width, image_height)
  95
  96     ctx = cairo.Context(surface)
  97     ctx.set_font_size(font_size)
  98     ctx.select_font_face(font_name, cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
  99
 100     if left_text == '0':
 101         left_text = None
 102     if right_text == '0':
 103         right_text = None
 104
 105     left_side_width = left_text_e.width + x_border*2
 106     right_side_width = right_text_e.width + x_border*2
 107
 108     rect_width = left_side_width + right_side_width
 109     rect_height = text_height + border*2
 110     if left_text is not None:
 111         draw_rounded_rectangle(ctx,x,y,rect_width,rect_height,radius, left_side_width, RRECT_LEFT_SIDE, right_text is None)
 112         linear = cairo.LinearGradient(x, y, x+left_side_width/2, y+rect_height/2)
 113         linear.add_color_stop_rgba(0, .7, .7, .7, .5)
 114         linear.add_color_stop_rgba(1, .4, .4, .4, .5)
 115         ctx.set_source(linear)
 116         ctx.fill_preserve()
 117         ctx.set_source_rgba(0, 0, 0, .4)
 118         ctx.set_line_width(1)
 119         ctx.stroke()
 120
 121         ctx.move_to(x+1+x_border-left_text_e.x_bearing, y+1+border+text_height)
 122         ctx.set_source_rgba( 0, 0, 0, 1)
 123         ctx.show_text(left_text)
 124         ctx.move_to(x+x_border-left_text_e.x_bearing, y+border+text_height)
 125         ctx.set_source_rgba( 1, 1, 1, 1)
 126         ctx.show_text(left_text)
 127
 128     if right_text is not None:
 129         draw_rounded_rectangle(ctx, x, y, rect_width, rect_height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 130         linear = cairo.LinearGradient(x+left_side_width, y, x+left_side_width+right_side_width/2, y+rect_height)
 131         linear.add_color_stop_rgba(0, 0, 0, 0, .9)
 132         linear.add_color_stop_rgba(1, 0, 0, 0, .5)
 133         ctx.set_source(linear)
 134         ctx.fill_preserve()
 135         ctx.set_source_rgba(0, 0, 0, .7)
 136         ctx.set_line_width(1)
 137         ctx.stroke()
 138
 139         ctx.move_to(x+1+x_border*3+left_text_e.width-right_text_e.x_bearing, y+1+border+text_height)
 140         ctx.set_source_rgba( 0, 0, 0, 1)
 141         ctx.show_text(right_text)
 142         ctx.move_to(x+x_border*3+left_text_e.width-right_text_e.x_bearing, y+border+text_height)
 143         ctx.set_source_rgba( 1, 1, 1, 1)
 144         ctx.show_text(right_text)
 145
 146     return surface
 147
 148
 149 def draw_pill_pixbuf(left_text, right_text):
 150     return cairo_surface_to_pixbuf(draw_text_pill(left_text, right_text))
 151
 152
 153 def cairo_surface_to_pixbuf(s):
 154     """
 155     Converts a Cairo surface to a Gtk Pixbuf by
 156     encoding it as PNG and using the PixbufLoader.
 157     """
 158     sio = StringIO.StringIO()
 159     try:
 160         s.write_to_png(sio)
 161     except:
 162         # Write an empty PNG file to the StringIO, so
 163         # in case of an error we have "something" to
 164         # load. This happens in PyCairo < 1.1.6, see:
 165         # http://webcvs.cairographics.org/pycairo/NEWS?view=markup
 166         # Thanks to Chris Arnold for reporting this bug
 167         sio.write('iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A\n/wD/oL2nkwAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9cMEQkqIyxn3RkAAAAZdEVYdENv\nbW1lbnQAQ3JlYXRlZCB3aXRoIEdJTVBXgQ4XAAAADUlEQVQI12NgYGBgAAAABQABXvMqOgAAAABJ\nRU5ErkJggg==\n'.decode('base64'))
 168
 169     pbl = gtk.gdk.PixbufLoader()
 170     pbl.write(sio.getvalue())
 171     pbl.close()
 172
 173     pixbuf = pbl.get_pixbuf()
 174     return pixbuf
 175
 176
 177 def progressbar_pixbuf(width, height, percentage):
 178     COLOR_BG = (.4, .4, .4, .4)
 179     COLOR_FG = (.2, .9, .2, 1.)
 180     COLOR_FG_HIGH = (1., 1., 1., .5)
 181     COLOR_BORDER = (0., 0., 0., 1.)
 182
 183     surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
 184     ctx = cairo.Context(surface)
 185
 186     padding = int(float(width)/8.0)
 187     bar_width = 2*padding
 188     bar_height = height - 2*padding
 189     bar_height_fill = bar_height*percentage
 190
 191     # Background
 192     ctx.rectangle(padding, padding, bar_width, bar_height)
 193     ctx.set_source_rgba(*COLOR_BG)
 194     ctx.fill()
 195
 196     # Foreground
 197     ctx.rectangle(padding, padding+bar_height-bar_height_fill, bar_width, bar_height_fill)
 198     ctx.set_source_rgba(*COLOR_FG)
 199     ctx.fill()
 200     ctx.rectangle(padding+bar_width/3, padding+bar_height-bar_height_fill, bar_width/4, bar_height_fill)
 201     ctx.set_source_rgba(*COLOR_FG_HIGH)
 202     ctx.fill()
 203
 204     # Border
 205     ctx.rectangle(padding-.5, padding-.5, bar_width+1, bar_height+1)
 206     ctx.set_source_rgba(*COLOR_BORDER)
 207     ctx.set_line_width(1.)
 208     ctx.stroke()
 209
 210     return cairo_surface_to_pixbuf(surface)
 211