compute histmap in idle callback and only if the histogram is expanded

diff --git a/src/bar_histogram.c b/src/bar_histogram.c
index edda23c..158de23 100644 (file)
--- a/src/bar_histogram.c
+++ b/src/bar_histogram.c
@@ -42,22 +42,46 @@ struct _PaneHistogramData
        gint histogram_height;
        GdkPixbuf *pixbuf;
        FileData *fd;
+       gboolean need_update;
+       gint idle_id;
 };
 
+static gboolean bar_pane_histogram_update_cb(gpointer data);
+
 
 static void bar_pane_histogram_update(PaneHistogramData *phd)
 {
-       const HistMap *histmap;
        if (phd->pixbuf) g_object_unref(phd->pixbuf);
        phd->pixbuf = NULL;
 
        if (!phd->histogram_width || !phd->histogram_height || !phd->fd) return;
 
+       /* histmap_get is relatively expensive, run it only when we really need it
+          and with lower priority than pixbuf_renderer 
+          FIXME: this does not work for fullscreen*/
+       if (GTK_WIDGET_DRAWABLE(phd->drawing_area))
+               {
+               if (phd->idle_id == -1) phd->idle_id = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, bar_pane_histogram_update_cb, phd, NULL);
+               }
+       else
+               {
+               phd->need_update = TRUE;
+               }
+}
+
+static gboolean bar_pane_histogram_update_cb(gpointer data)
+{
+       const HistMap *histmap;
+       PaneHistogramData *phd = data;
+
+       phd->idle_id = -1;
+       phd->need_update = FALSE;
+       
        gtk_widget_queue_draw_area(GTK_WIDGET(phd->drawing_area), 0, 0, phd->histogram_width, phd->histogram_height);
        
        histmap = histmap_get(phd->fd);
        
-       if (!histmap) return;
+       if (!histmap) return FALSE;
        
        phd->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, phd->histogram_width, phd->histogram_height);
        gdk_pixbuf_fill(phd->pixbuf, 0xffffffff);
@@ -66,6 +90,7 @@ static void bar_pane_histogram_update(PaneHistogramData *phd)
 #if GTK_CHECK_VERSION(2,12,0)
        gtk_widget_set_tooltip_text(phd->drawing_area, histogram_label(phd->histogram));
 #endif
+       return FALSE;
 }
 
 
@@ -109,7 +134,14 @@ static void bar_pane_histogram_notify_cb(FileData *fd, NotifyType type, gpointer
 static gboolean bar_pane_histogram_expose_event_cb (GtkWidget *widget, GdkEventExpose *event, gpointer data)
 {
        PaneHistogramData *phd = data;
-       if (!phd || !phd->pixbuf) return TRUE;
+       if (!phd) return TRUE;
+       
+       if (phd->need_update)
+               {
+               bar_pane_histogram_update(phd);
+               }
+       
+       if (!phd->pixbuf) return TRUE;
        
        gdk_draw_pixbuf(widget->window,
                        widget->style->fg_gc[GTK_WIDGET_STATE (widget)],
@@ -143,7 +175,8 @@ static void bar_pane_histogram_close(GtkWidget *pane)
 static void bar_pane_histogram_destroy(GtkWidget *widget, gpointer data)
 {
        PaneHistogramData *phd = data;
-
+       
+       g_source_remove(phd->idle_id);
        file_data_unregister_notify_func(bar_pane_histogram_notify_cb, phd);
 
        file_data_unref(phd->fd);
@@ -304,6 +337,7 @@ GtkWidget *bar_pane_histogram_new(const gchar *title, gint height, gint expanded
        phd->pane.pane_write_config = bar_pane_histogram_write_config;
        phd->pane.title = g_strdup(title);
        phd->pane.expanded = expanded;
+       phd->idle_id = -1;
        
        phd->histogram = histogram_new();