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     if left_side_width is None:
  47         left_side_width = flw/2
  48
  49     x = int(x)
  50     offset = 0
  51     if close: offset = 0.5
  52
  53     if sides_to_draw & RRECT_LEFT_SIDE:
  54         ctx.move_to(x+int(left_side_width)-offset, y+h)
  55         ctx.line_to(x+r, y+h)
  56         ctx.curve_to(x, y+h, x, y+h, x, y+h-r)
  57         ctx.line_to(x, y+r)
  58         ctx.curve_to(x, y, x, y, x+r, y)
  59         ctx.line_to(x+int(left_side_width)-offset, y)
  60         if close:
  61             ctx.line_to(x+int(left_side_width)-offset, y+h)
  62
  63     if sides_to_draw & RRECT_RIGHT_SIDE:
  64         ctx.move_to(x+int(left_side_width)+offset, y)
  65         ctx.line_to(x+w-r, y)
  66         ctx.curve_to(x+w, y, x+w, y, x+w, y+r)
  67         ctx.line_to(x+w, y+h-r)
  68         ctx.curve_to(x+w, y+h, x+w, y+h, x+w-r, y+h)
  69         ctx.line_to(x+int(left_side_width)+offset, y+h)
  70         if close:
  71             ctx.line_to(x+int(left_side_width)+offset, y)
  72
  73
  74 def rounded_rectangle(ctx, x, y, width, height, radius=4.):
  75     """Simple rounded rectangle algorithmn
  76
  77     http://www.cairographics.org/samples/rounded_rectangle/
  78     """
  79     degrees = math.pi / 180.
  80     ctx.new_sub_path()
  81     if width > radius:
  82         ctx.arc(x + width - radius, y + radius, radius, -90. * degrees, 0)
  83         ctx.arc(x + width - radius, y + height - radius, radius, 0, 90. * degrees)
  84         ctx.arc(x + radius, y + height - radius, radius, 90. * degrees, 180. * degrees)
  85         ctx.arc(x + radius, y + radius, radius, 180. * degrees, 270. * degrees)
  86     ctx.close_path()
  87
  88
  89 def draw_text_box_centered(ctx, widget, w_width, w_height, text, font_desc=None, add_progress=None):
  90     style = widget.rc_get_style()
  91     text_color = style.text[gtk.STATE_PRELIGHT]
  92     red, green, blue = text_color.red, text_color.green, text_color.blue
  93     text_color = [float(x)/65535. for x in (red, green, blue)]
  94     text_color.append(.5)
  95
  96     if font_desc is None:
  97         font_desc = style.font_desc
  98         font_desc.set_size(14*pango.SCALE)
  99
 100     pango_context = widget.create_pango_context()
 101     layout = pango.Layout(pango_context)
 102     layout.set_font_description(font_desc)
 103     layout.set_text(text)
 104     width, height = layout.get_pixel_size()
 105
 106     ctx.move_to(w_width/2-width/2, w_height/2-height/2)
 107     ctx.set_source_rgba(*text_color)
 108     ctx.show_layout(layout)
 109
 110     # Draw an optional progress bar below the text (same width)
 111     if add_progress is not None:
 112         bar_height = 10
 113         ctx.set_source_rgba(*text_color)
 114         ctx.set_line_width(1.)
 115         rounded_rectangle(ctx, w_width/2-width/2-.5, w_height/2+height-.5, width+1, bar_height+1)
 116         ctx.stroke()
 117         rounded_rectangle(ctx, w_width/2-width/2, w_height/2+height, int(width*add_progress)+.5, bar_height)
 118         ctx.fill()
 119
 120
 121 def draw_text_pill(left_text, right_text, x=0, y=0, border=2, radius=14, font_desc=None):
 122     if gpodder.ui.fremantle:
 123         border += 3
 124     # Create temporary context to calculate the text size
 125     ctx = cairo.Context(cairo.ImageSurface(cairo.FORMAT_ARGB32, 1, 1))
 126
 127     # Use GTK+ style of a normal Button
 128     widget = gtk.Label()
 129     style = widget.rc_get_style()
 130
 131     x_border = border*2
 132
 133     if font_desc is None:
 134         font_desc = style.font_desc
 135         font_desc.set_weight(pango.WEIGHT_BOLD)
 136
 137     pango_context = widget.create_pango_context()
 138     layout_left = pango.Layout(pango_context)
 139     layout_left.set_font_description(font_desc)
 140     layout_left.set_text(left_text)
 141     layout_right = pango.Layout(pango_context)
 142     layout_right.set_font_description(font_desc)
 143     layout_right.set_text(right_text)
 144
 145     width_left, height_left = layout_left.get_pixel_size()
 146     width_right, height_right = layout_right.get_pixel_size()
 147
 148     text_height = max(height_left, height_right)
 149
 150     image_height = int(y+text_height+border*2)
 151     image_width = int(x+width_left+width_right+x_border*4)
 152     surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, image_width, image_height)
 153
 154     ctx = pangocairo.CairoContext(cairo.Context(surface))
 155
 156     if left_text == '0':
 157         left_text = None
 158     if right_text == '0':
 159         right_text = None
 160
 161     left_side_width = width_left + x_border*2
 162     right_side_width = width_right + x_border*2
 163
 164     rect_width = left_side_width + right_side_width
 165     rect_height = text_height + border*2
 166     if left_text is not None:
 167         draw_rounded_rectangle(ctx,x,y,rect_width,rect_height,radius, left_side_width, RRECT_LEFT_SIDE, right_text is None)
 168         linear = cairo.LinearGradient(x, y, x+left_side_width/2, y+rect_height/2)
 169         linear.add_color_stop_rgba(0, .8, .8, .8, .5)
 170         linear.add_color_stop_rgba(.4, .8, .8, .8, .7)
 171         linear.add_color_stop_rgba(.6, .8, .8, .8, .6)
 172         linear.add_color_stop_rgba(.9, .8, .8, .8, .8)
 173         linear.add_color_stop_rgba(1, .8, .8, .8, .9)
 174         ctx.set_source(linear)
 175         ctx.fill()
 176         xpos, ypos, width_left, height = x+1, y+1, left_side_width, rect_height-2
 177         if right_text is None:
 178             width_left -= 2
 179         draw_rounded_rectangle(ctx, xpos, ypos, rect_width, height, radius, width_left, RRECT_LEFT_SIDE, right_text is None)
 180         ctx.set_source_rgba(1., 1., 1., .3)
 181         ctx.set_line_width(1)
 182         ctx.stroke()
 183         draw_rounded_rectangle(ctx,x,y,rect_width,rect_height,radius, left_side_width, RRECT_LEFT_SIDE, right_text is None)
 184         ctx.set_source_rgba(.2, .2, .2, .6)
 185         ctx.set_line_width(1)
 186         ctx.stroke()
 187
 188         ctx.move_to(x+x_border, y+1+border)
 189         ctx.set_source_rgba( 0, 0, 0, 1)
 190         ctx.show_layout(layout_left)
 191         ctx.move_to(x-1+x_border, y+border)
 192         ctx.set_source_rgba( 1, 1, 1, 1)
 193         ctx.show_layout(layout_left)
 194
 195     if right_text is not None:
 196         draw_rounded_rectangle(ctx, x, y, rect_width, rect_height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 197         linear = cairo.LinearGradient(x+left_side_width, y, x+left_side_width+right_side_width/2, y+rect_height)
 198         linear.add_color_stop_rgba(0, .2, .2, .2, .9)
 199         linear.add_color_stop_rgba(.4, .2, .2, .2, .8)
 200         linear.add_color_stop_rgba(.6, .2, .2, .2, .6)
 201         linear.add_color_stop_rgba(.9, .2, .2, .2, .7)
 202         linear.add_color_stop_rgba(1, .2, .2, .2, .5)
 203         ctx.set_source(linear)
 204         ctx.fill()
 205         xpos, ypos, width, height = x, y+1, rect_width-1, rect_height-2
 206         if left_text is None:
 207             xpos, width = x+1, rect_width-2
 208         draw_rounded_rectangle(ctx, xpos, ypos, width, height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 209         ctx.set_source_rgba(1., 1., 1., .3)
 210         ctx.set_line_width(1)
 211         ctx.stroke()
 212         draw_rounded_rectangle(ctx, x, y, rect_width, rect_height, radius, left_side_width, RRECT_RIGHT_SIDE, left_text is None)
 213         ctx.set_source_rgba(.1, .1, .1, .6)
 214         ctx.set_line_width(1)
 215         ctx.stroke()
 216
 217         ctx.move_to(x+left_side_width+x_border, y+1+border)
 218         ctx.set_source_rgba( 0, 0, 0, 1)
 219         ctx.show_layout(layout_right)
 220         ctx.move_to(x-1+left_side_width+x_border, y+border)
 221         ctx.set_source_rgba( 1, 1, 1, 1)
 222         ctx.show_layout(layout_right)
 223
 224     return surface
 225
 226
 227 def draw_pill_pixbuf(left_text, right_text):
 228     return cairo_surface_to_pixbuf(draw_text_pill(left_text, right_text))
 229
 230
 231 def cairo_surface_to_pixbuf(s):
 232     """
 233     Converts a Cairo surface to a Gtk Pixbuf by
 234     encoding it as PNG and using the PixbufLoader.
 235     """
 236     sio = StringIO.StringIO()
 237     try:
 238         s.write_to_png(sio)
 239     except:
 240         # Write an empty PNG file to the StringIO, so
 241         # in case of an error we have "something" to
 242         # load. This happens in PyCairo < 1.1.6, see:
 243         # http://webcvs.cairographics.org/pycairo/NEWS?view=markup
 244         # Thanks to Chris Arnold for reporting this bug
 245         sio.write('iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A\n/wD/oL2nkwAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9cMEQkqIyxn3RkAAAAZdEVYdENv\nbW1lbnQAQ3JlYXRlZCB3aXRoIEdJTVBXgQ4XAAAADUlEQVQI12NgYGBgAAAABQABXvMqOgAAAABJ\nRU5ErkJggg==\n'.decode('base64'))
 246
 247     pbl = gtk.gdk.PixbufLoader()
 248     pbl.write(sio.getvalue())
 249     pbl.close()
 250
 251     pixbuf = pbl.get_pixbuf()
 252     return pixbuf
 253
 254 def progressbar_pixbuf(width, height, percentage):
 255     COLOR_BG = (.4, .4, .4, .4)
 256     COLOR_FG = (.2, .9, .2, 1.)
 257     COLOR_FG_HIGH = (1., 1., 1., .5)
 258     COLOR_BORDER = (0., 0., 0., 1.)
 259
 260     surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
 261     ctx = cairo.Context(surface)
 262
 263     padding = int(float(width)/8.0)
 264     bar_width = 2*padding
 265     bar_height = height - 2*padding
 266     bar_height_fill = bar_height*percentage
 267
 268     # Background
 269     ctx.rectangle(padding, padding, bar_width, bar_height)
 270     ctx.set_source_rgba(*COLOR_BG)
 271     ctx.fill()
 272
 273     # Foreground
 274     ctx.rectangle(padding, padding+bar_height-bar_height_fill, bar_width, bar_height_fill)
 275     ctx.set_source_rgba(*COLOR_FG)
 276     ctx.fill()
 277     ctx.rectangle(padding+bar_width/3, padding+bar_height-bar_height_fill, bar_width/4, bar_height_fill)
 278     ctx.set_source_rgba(*COLOR_FG_HIGH)
 279     ctx.fill()
 280
 281     # Border
 282     ctx.rectangle(padding-.5, padding-.5, bar_width+1, bar_height+1)
 283     ctx.set_source_rgba(*COLOR_BORDER)
 284     ctx.set_line_width(1.)
 285     ctx.stroke()
 286
 287     return cairo_surface_to_pixbuf(surface)
 288