src/gpodder/gtkui/draw.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # gPodder - A media aggregator and podcast client
   4 # Copyright (c) 2005-2010 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 import gpodder
  27
  28 import gtk
  29 import pango
  30 import pangocairo
  31 import cairo
  32 import StringIO
  33 import math
  34
  35
  36 class TextExtents(object):
  37     def __init__(self, ctx, text):
  38         tuple = ctx.text_extents(text)
  39         (self.x_bearing, self.y_bearing, self.width, self.height, self.x_advance, self.y_advance) = tuple
  40
  41
  42 RRECT_LEFT_SIDE = 1
  43 RRECT_RIGHT_SIDE = 2
  44
  45 def draw_rounded_rectangle(ctx, x, y, w, h, r=10, left_side_width = None, sides_to_draw=0, close=False):
  46     assert left_side_width is not None
  47
  48     x = int(x)
  49     offset = 0
  50     if close: offset = 0.5
  51
  52     if sides_to_draw & RRECT_LEFT_SIDE:
  53         ctx.move_to(x+int(left_side_width)-offset, y+h)
  54         ctx.line_to(x+r, y+h)
  55         ctx.curve_to(x, y+h, x, y+h, x, y+h-r)
  56         ctx.line_to(x, y+r)
  57         ctx.curve_to(x, y, x, y, x+r, y)
  58         ctx.line_to(x+int(left_side_width)-offset, y)
  59         if close:
  60             ctx.line_to(x+int(left_side_width)-offset, y+h)
  61
  62     if sides_to_draw & RRECT_RIGHT_SIDE:
  63         ctx.move_to(x+int(left_side_width)+offset, y)
  64         ctx.line_to(x+w-r, y)
  65         ctx.curve_to(x+w, y, x+w, y, x+w, y+r)
  66         ctx.line_to(x+w, y+h-r)
  67         ctx.curve_to(x+w, y+h, x+w, y+h, x+w-r, y+h)
  68         ctx.line_to(x+int(left_side_width)+offset, y+h)
  69         if close:
  70             ctx.line_to(x+int(left_side_width)+offset, y)
  71
  72
  73 def rounded_rectangle(ctx, x, y, width, height, radius=4.):
  74     """Simple rounded rectangle algorithmn
  75
  76     http://www.cairographics.org/samples/rounded_rectangle/
  77     """
  78     degrees = math.pi / 180.
  79     ctx.new_sub_path()
  80     if width > radius:
  81         ctx.arc(x + width - radius, y + radius, radius, -90. * degrees, 0)
  82         ctx.arc(x + width - radius, y + height - radius, radius, 0, 90. * degrees)
  83         ctx.arc(x + radius, y + height - radius, radius, 90. * degrees, 180. * degrees)
  84         ctx.arc(x + radius, y + radius, radius, 180. * degrees, 270. * degrees)
  85     ctx.close_path()
  86
  87
  88 def draw_text_box_centered(ctx, widget, w_width, w_height, text, font_desc=None, add_progress=None):
  89     style = widget.rc_get_style()
  90     text_color = style.text[gtk.STATE_PRELIGHT]
  91     red, green, blue = text_color.red, text_color.green, text_color.blue
  92     text_color = [float(x)/65535. for x in (red, green, blue)]
  93     text_color.append(.5)
  94
  95     if font_desc is None:
  96         font_desc = style.font_desc
  97         font_desc.set_size(14*pango.SCALE)
  98
  99     pango_context = widget.create_pango_context()
 100     layout = pango.Layout(pango_context)
 101     layout.set_font_description(font_desc)
 102     layout.set_text(text)
 103     width, height = layout.get_pixel_size()
 104
 105     ctx.move_to(w_width/2-width/2, w_height/2-height/2)
 106     ctx.set_source_rgba(*text_color)
 107     ctx.show_layout(layout)
 108
 109     # Draw an optional progress bar below the text (same width)
 110     if add_progress is not None:
 111         bar_height = 10
 112         ctx.set_source_rgba(*text_color)
 113         ctx.set_line_width(1.)
 114         rounded_rectangle(ctx, w_width/2-width/2-.5, w_height/2+height-.5, width+1, bar_height+1)
 115         ctx.stroke()
 116         rounded_rectangle(ctx, w_width/2-width/2, w_height/2+height, int(width*add_progress)+.5, bar_height)
 117         ctx.fill()
 118
 119
 120 def draw_text_pill(left_text, right_text, x=0, y=0, border=2, radius=14, font_desc=None):
 121     if gpodder.ui.fremantle:
 122         border += 3
 123     # Create temporary context to calculate the text size
 124     ctx = cairo.Context(cairo.ImageSurface(cairo.FORMAT_ARGB32, 1, 1))
 125
 126     # Use GTK+ style of a normal Button
 127     widget = gtk.Label()
 128     style = widget.rc_get_style()
 129
 130     x_border = border*2
 131
 132     if font_desc is None:
 133         font_desc = style.font_desc
 134         font_desc.set_weight(pango.WEIGHT_BOLD)
 135
 136     pango_context = widget.create_pango_context()
 137     layout_left = pango.Layout(pango_context)
 138     layout_left.set_font_description(font_desc)
 139     layout_left.set_text(left_text)
 140     layout_right = pango.Layout(pango_context)
 141     layout_right.set_font_description(font_desc)
 142     layout_right.set_text(right_text)
 143
 144     width_left, height_left = layout_left.get_pixel_size()
 145     width_right, height_right = layout_right.get_pixel_size()
 146
 147     text_height = max(height_left, height_right)
 148
 149     image_height = int(y+text_height+border*2)
 150     image_width = int(x+width_left+width_right+x_border*4)
 151     surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, image_width, image_height)
 152
 153     ctx = pangocairo.CairoContext(cairo.Context(surface))
 154
 155     if left_text == '0':
 156         left_text = None
 157     if right_text == '0':
 158         right_text = None
 159
 160     left_side_width = width_left + x_border*2
 161     right_side_width = width_right + x_border*2
 162
 163     rect_width = left_side_width + right_side_width
 164     rect_height = text_height + border*2
 165     if left_text is not None:
 166         draw_rounded_rectangle(ctx,x,y,rect_width,rect_height,radius, left_side_width, RRECT_LEFT_SIDE, right_text is None)
 167         linear = cairo.LinearGradient(x, y, x+left_side_width/2, y+rect_height/2)
 168         linear.add_color_stop_rgba(0, .8, .8, .8, .5)
 169         linear.add_color_stop_rgba(.4, .8, .8, .8, .7)
 170         linear.add_color_stop_rgba(.6, .8, .8, .8, .6)
 171         linear.add_color_stop_rgba(.9, .8, .8, .8, .8)
 172         linear.add_color_stop_rgba(1, .8, .8, .8, .9)
 173         ctx.set_source(linear)
 174         ctx.fill()
 175         xpos, ypos, width_left, height = x+1, y+1, left_side_width, rect_height-2
 176         if right_text is None:
 177             width_left -= 2
 178         draw_rounded_rectangle(ctx, xpos, ypos, rect_width, height, radius, width_left, RRECT_LEFT_SIDE, right_text is None)
 179         ctx.set_source_rgba(1., 1., 1., .3)
 180         ctx.set_line_width(1)
 181         ctx.stroke()
 182         draw_rounded_rectangle(ctx,x,y,rect_width,rect_height,radius, left_side_width, RRECT_LEFT_SIDE, right_text is None)
 183         ctx.set_source_rgba(.2, .2, .2, .6)
 184         ctx.set_line_width(1)
 185         ctx.stroke()
 186
 187         ctx.move_to(x+x_border, y+1+border)
 188         ctx.set_source_rgba( 0, 0, 0, 1)
 189         ctx.show_layout(layout_left)
 190         ctx.move_to(x-1+x_border, y+border)
 191         ctx.set_source_rgba( 1, 1, 1, 1)
 192         ctx.show_layout(layout_left)
 193
 194     if right_text is not None:
 195         draw_rounded_rectangle(ctx, x, y, rect_width, rect_height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 196         linear = cairo.LinearGradient(x+left_side_width, y, x+left_side_width+right_side_width/2, y+rect_height)
 197         linear.add_color_stop_rgba(0, .2, .2, .2, .9)
 198         linear.add_color_stop_rgba(.4, .2, .2, .2, .8)
 199         linear.add_color_stop_rgba(.6, .2, .2, .2, .6)
 200         linear.add_color_stop_rgba(.9, .2, .2, .2, .7)
 201         linear.add_color_stop_rgba(1, .2, .2, .2, .5)
 202         ctx.set_source(linear)
 203         ctx.fill()
 204         xpos, ypos, width, height = x, y+1, rect_width-1, rect_height-2
 205         if left_text is None:
 206             xpos, width = x+1, rect_width-2
 207         draw_rounded_rectangle(ctx, xpos, ypos, width, height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 208         ctx.set_source_rgba(1., 1., 1., .3)
 209         ctx.set_line_width(1)
 210         ctx.stroke()
 211         draw_rounded_rectangle(ctx, x, y, rect_width, rect_height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 212         ctx.set_source_rgba(.1, .1, .1, .6)
 213         ctx.set_line_width(1)
 214         ctx.stroke()
 215
 216         ctx.move_to(x+left_side_width+x_border, y+1+border)
 217         ctx.set_source_rgba( 0, 0, 0, 1)
 218         ctx.show_layout(layout_right)
 219         ctx.move_to(x-1+left_side_width+x_border, y+border)
 220         ctx.set_source_rgba( 1, 1, 1, 1)
 221         ctx.show_layout(layout_right)
 222
 223     return surface
 224
 225
 226 def draw_pill_pixbuf(left_text, right_text):
 227     return cairo_surface_to_pixbuf(draw_text_pill(left_text, right_text))
 228
 229
 230 def cairo_surface_to_pixbuf(s):
 231     """
 232     Converts a Cairo surface to a Gtk Pixbuf by
 233     encoding it as PNG and using the PixbufLoader.
 234     """
 235     sio = StringIO.StringIO()
 236     try:
 237         s.write_to_png(sio)
 238     except:
 239         # Write an empty PNG file to the StringIO, so
 240         # in case of an error we have "something" to
 241         # load. This happens in PyCairo < 1.1.6, see:
 242         # http://webcvs.cairographics.org/pycairo/NEWS?view=markup
 243         # Thanks to Chris Arnold for reporting this bug
 244         sio.write('iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A\n/wD/oL2nkwAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9cMEQkqIyxn3RkAAAAZdEVYdENv\nbW1lbnQAQ3JlYXRlZCB3aXRoIEdJTVBXgQ4XAAAADUlEQVQI12NgYGBgAAAABQABXvMqOgAAAABJ\nRU5ErkJggg==\n'.decode('base64'))
 245
 246     pbl = gtk.gdk.PixbufLoader()
 247     pbl.write(sio.getvalue())
 248     pbl.close()
 249
 250     pixbuf = pbl.get_pixbuf()
 251     return pixbuf
 252
 253 def progressbar_pixbuf(width, height, percentage):
 254     COLOR_BG = (.4, .4, .4, .4)
 255     COLOR_FG = (.2, .9, .2, 1.)
 256     COLOR_FG_HIGH = (1., 1., 1., .5)
 257     COLOR_BORDER = (0., 0., 0., 1.)
 258
 259     surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
 260     ctx = cairo.Context(surface)
 261
 262     padding = int(float(width)/8.0)
 263     bar_width = 2*padding
 264     bar_height = height - 2*padding
 265     bar_height_fill = bar_height*percentage
 266
 267     # Background
 268     ctx.rectangle(padding, padding, bar_width, bar_height)
 269     ctx.set_source_rgba(*COLOR_BG)
 270     ctx.fill()
 271
 272     # Foreground
 273     ctx.rectangle(padding, padding+bar_height-bar_height_fill, bar_width, bar_height_fill)
 274     ctx.set_source_rgba(*COLOR_FG)
 275     ctx.fill()
 276     ctx.rectangle(padding+bar_width/3, padding+bar_height-bar_height_fill, bar_width/4, bar_height_fill)
 277     ctx.set_source_rgba(*COLOR_FG_HIGH)
 278     ctx.fill()
 279
 280     # Border
 281     ctx.rectangle(padding-.5, padding-.5, bar_width+1, bar_height+1)
 282     ctx.set_source_rgba(*COLOR_BORDER)
 283     ctx.set_line_width(1.)
 284     ctx.stroke()
 285
 286     return cairo_surface_to_pixbuf(surface)
 287