[evince] EvPresentationView: Render correctly on hi-dpi displays

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 37c13b386a89156e616dc24db2cf6a3b64c4c6a7
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Thu Feb 27 19:22:55 2014 -0500

    EvPresentationView: Render correctly on hi-dpi displays
    
    Create rendering jobs with a scale that incorporate the scale factor of
    the widget, and then use cairo_surface_set_device_scale() to make the
    resulting surfaces render at the correct size. Handle changes to the scale
    factor both for the cached surfaces, and also for the monitor dimensions,
    which are reported in scaled coordinates.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=723431

 libview/ev-view-presentation.c |   70 ++++++++++++++++++++++++++++++++++------
 1 files changed, 60 insertions(+), 10 deletions(-)
---
diff --git a/libview/ev-view-presentation.c b/libview/ev-view-presentation.c
index 678b456..ea9aee0 100644
--- a/libview/ev-view-presentation.c
+++ b/libview/ev-view-presentation.c
@@ -274,11 +274,35 @@ ev_view_presentation_transition_animation_frame (EvViewPresentation *pview,
        gtk_widget_queue_draw (GTK_WIDGET (pview));
 }
 
+static cairo_surface_t *
+get_surface_from_job (EvViewPresentation *pview,
+                      EvJob              *job)
+{
+        cairo_surface_t *surface;
+
+        if (!job)
+                return NULL;
+
+        surface = EV_JOB_RENDER(job)->surface;
+        if (!surface)
+                return NULL;
+
+#ifdef HAVE_HIDPI_SUPPORT
+        {
+                int scale_factor = gtk_widget_get_scale_factor (GTK_WIDGET (pview));
+                cairo_surface_set_device_scale (surface, scale_factor, scale_factor);
+        }
+#endif
+
+        return surface;
+}
+
 static void
 ev_view_presentation_animation_start (EvViewPresentation *pview,
                                      gint                new_page)
 {
        EvTransitionEffect *effect = NULL;
+       EvJob              *job;
        cairo_surface_t    *surface;
        gint                jump;
 
@@ -302,11 +326,12 @@ ev_view_presentation_animation_start (EvViewPresentation *pview,
 
        jump = new_page - pview->current_page;
        if (jump == -1)
-               surface = pview->prev_job ? EV_JOB_RENDER (pview->prev_job)->surface : NULL;
+               job = pview->prev_job;
        else if (jump == 1)
-               surface = pview->next_job ? EV_JOB_RENDER (pview->next_job)->surface : NULL;
+               job = pview->next_job;
        else
-               surface = NULL;
+               job = NULL;
+       surface = get_surface_from_job (pview, job);
        if (surface)
                ev_transition_animation_set_dest_surface (pview->animation, surface);
 
@@ -333,7 +358,7 @@ job_finished_cb (EvJob              *job,
 
        if (pview->animation) {
                ev_transition_animation_set_dest_surface (pview->animation,
-                                                         job_render->surface);
+                                                         get_surface_from_job (pview, job));
        } else {
                ev_view_presentation_transition_start (pview);
                gtk_widget_queue_draw (GTK_WIDGET (pview));
@@ -352,6 +377,13 @@ ev_view_presentation_schedule_new_job (EvViewPresentation *pview,
                return NULL;
 
         ev_view_presentation_get_view_size (pview, page, &view_width, &view_height);
+#ifdef HAVE_HIDPI_SUPPORT
+       {
+               gint device_scale = gtk_widget_get_scale_factor (GTK_WIDGET (pview));
+               view_width *= device_scale;
+               view_height *= device_scale;
+       }
+#endif
         job = ev_job_render_new (pview->document, page, pview->rotation, 0.,
                                  view_width, view_height);
        g_signal_connect (job, "finished",
@@ -1069,7 +1101,7 @@ ev_view_presentation_draw (GtkWidget *widget,
                return TRUE;
        }
 
-       surface = pview->curr_job ? EV_JOB_RENDER (pview->curr_job)->surface : NULL;
+       surface = get_surface_from_job (pview, pview->curr_job);
        if (surface) {
                ev_view_presentation_update_current_surface (pview, surface);
        } else if (pview->current_surface) {
@@ -1224,18 +1256,25 @@ ev_view_presentation_motion_notify_event (GtkWidget      *widget,
        return FALSE;
 }
 
-static gboolean
-init_presentation (GtkWidget *widget)
+static void
+ev_view_presentation_update_monitor_geometry (EvViewPresentation *pview)
 {
-       EvViewPresentation *pview = EV_VIEW_PRESENTATION (widget);
-       GdkScreen          *screen = gtk_widget_get_screen (widget);
+       GdkScreen          *screen = gtk_widget_get_screen (GTK_WIDGET (pview));
        GdkRectangle        monitor;
        gint                monitor_num;
 
-       monitor_num = gdk_screen_get_monitor_at_window (screen, gtk_widget_get_window (widget));
+       monitor_num = gdk_screen_get_monitor_at_window (screen, gtk_widget_get_window (GTK_WIDGET (pview)));
        gdk_screen_get_monitor_geometry (screen, monitor_num, &monitor);
        pview->monitor_width = monitor.width;
        pview->monitor_height = monitor.height;
+}
+
+static gboolean
+init_presentation (GtkWidget *widget)
+{
+       EvViewPresentation *pview = EV_VIEW_PRESENTATION (widget);
+
+       ev_view_presentation_update_monitor_geometry (pview);
 
        ev_view_presentation_update_current_page (pview, pview->current_page);
        ev_view_presentation_hide_cursor_timeout_start (pview);
@@ -1391,6 +1430,14 @@ ev_view_presentation_get_property (GObject    *object,
         }
 }
 
+static void
+ev_view_presentation_notify_scale_factor (EvViewPresentation *pview)
+{
+        ev_view_presentation_update_monitor_geometry (pview);
+        ev_view_presentation_reset_jobs (pview);
+        ev_view_presentation_update_current_page (pview, pview->current_page);
+}
+
 static GObject *
 ev_view_presentation_constructor (GType                  type,
                                  guint                  n_construct_properties,
@@ -1410,6 +1457,9 @@ ev_view_presentation_constructor (GType                  type,
                ev_page_cache_set_flags (pview->page_cache, EV_PAGE_DATA_INCLUDE_LINKS);
        }
 
+        g_signal_connect (object, "notify::scale-factor",
+                          G_CALLBACK (ev_view_presentation_notify_scale_factor), NULL);
+
        return object;
 }