[gnome-builder] omni-gutter: scale diagnostic icons with text

[Christian Hergert <chergert src gnome org>]

commit de65b2b883cf309f00d23649f23116a72dd6c191
Author: Christian Hergert <chergert redhat com>
Date:   Sun Jan 14 23:03:45 2018 -0800

    omni-gutter: scale diagnostic icons with text
    
    This has a basic implementation to track the size of the scaled
    icon text in the editor. The diagnostic surfaces are reloaded
    to be somewhat close to that text scale (following rather common
    icon sizing).
    
    Fixes #255

 src/libide/sourceview/ide-omni-gutter-renderer.c | 60 +++++++++++++++++++-----
 1 file changed, 47 insertions(+), 13 deletions(-)
---
diff --git a/src/libide/sourceview/ide-omni-gutter-renderer.c 
b/src/libide/sourceview/ide-omni-gutter-renderer.c
index 7db5de881..f913f0f67 100644
--- a/src/libide/sourceview/ide-omni-gutter-renderer.c
+++ b/src/libide/sourceview/ide-omni-gutter-renderer.c
@@ -51,7 +51,6 @@
  * Since: 3.28
  */
 
-#define DIAGNOSTICS_SIZE 16
 #define ARROW_WIDTH      5
 #define CHANGE_WIDTH     2
 #define DELETE_WIDTH     5.0
@@ -157,6 +156,12 @@ struct _IdeOmniGutterRenderer
    */
   gint number_width;
 
+  /*
+   * Calculated size for diagnostics, to be a nearest icon-size based
+   * on the height of the line text.
+   */
+  gint diag_size;
+
   /*
    * Some users might want to toggle off individual features of the
    * omni gutter, and these boolean properties provide that. Other
@@ -216,6 +221,8 @@ typedef struct
   guint is_note : 1;
 } LineInfo;
 
+static void ide_omni_gutter_renderer_reload_icons (IdeOmniGutterRenderer *self);
+
 G_DEFINE_TYPE (IdeOmniGutterRenderer, ide_omni_gutter_renderer, GTK_SOURCE_TYPE_GUTTER_RENDERER)
 
 static GParamSpec *properties [N_PROPS];
@@ -498,6 +505,22 @@ count_num_digits (gint num_lines)
     return 10;
 }
 
+static gint
+calculate_diagnostics_size (gint height)
+{
+  static guint sizes[] = { 64, 48, 32, 24, 16, 8 };
+
+  height -= 2; /* Subtract padding */
+
+  for (guint i = 0; i < G_N_ELEMENTS (sizes); i++)
+    {
+      if (height >= sizes[i])
+        return sizes[i];
+    }
+
+  return 16;
+}
+
 static void
 ide_omni_gutter_renderer_recalculate_size (IdeOmniGutterRenderer *self)
 {
@@ -551,10 +574,17 @@ ide_omni_gutter_renderer_recalculate_size (IdeOmniGutterRenderer *self)
    */
   pango_layout_get_pixel_size (layout, &self->number_width, &height);
 
+  /*
+   * Calculate the nearest size for diagnostics so they scale somewhat
+   * reasonable with the character size.
+   */
+  self->diag_size = calculate_diagnostics_size (MAX (16, height));
+  g_assert (self->diag_size > 0);
+
   /* Now calculate the size based on enabled features */
   size = 2;
   if (self->show_line_diagnostics)
-    size += DIAGNOSTICS_SIZE + 2;
+    size += self->diag_size + 2;
   if (self->show_line_numbers)
     size += self->number_width + 2;
 
@@ -582,6 +612,7 @@ ide_omni_gutter_renderer_notify_font_desc (IdeOmniGutterRenderer *self,
   g_assert (IDE_IS_SOURCE_VIEW (view));
 
   ide_omni_gutter_renderer_recalculate_size (self);
+  ide_omni_gutter_renderer_reload_icons (self);
 }
 
 static void
@@ -947,6 +978,7 @@ draw_diagnostic (IdeOmniGutterRenderer        *self,
                  cairo_t                      *cr,
                  GdkRectangle                 *area,
                  LineInfo                     *info,
+                 guint                         diag_size,
                  GtkSourceGutterRendererState  state)
 {
   cairo_surface_t *surface = NULL;
@@ -954,6 +986,7 @@ draw_diagnostic (IdeOmniGutterRenderer        *self,
   g_assert (IDE_IS_OMNI_GUTTER_RENDERER (self));
   g_assert (cr != NULL);
   g_assert (area != NULL);
+  g_assert (diag_size > 0);
 
   if (IS_BREAKPOINT (info) || (state & GTK_SOURCE_GUTTER_RENDERER_STATE_PRELIT))
     {
@@ -978,12 +1011,12 @@ draw_diagnostic (IdeOmniGutterRenderer        *self,
     {
       cairo_rectangle (cr,
                        area->x + 2,
-                       area->y + ((area->height - DIAGNOSTICS_SIZE) / 2),
-                       DIAGNOSTICS_SIZE, DIAGNOSTICS_SIZE);
+                       area->y + ((area->height - diag_size) / 2),
+                       diag_size, diag_size);
       cairo_set_source_surface (cr,
                                 surface,
                                 area->x + 2,
-                                area->y + ((area->height - DIAGNOSTICS_SIZE) / 2));
+                                area->y + ((area->height - diag_size) / 2));
       cairo_paint (cr);
     }
 }
@@ -1072,7 +1105,7 @@ ide_omni_gutter_renderer_draw (GtkSourceGutterRenderer      *renderer,
        * color for symbolic icon).
        */
       if (self->show_line_diagnostics && IS_DIAGNOSTIC (info))
-        draw_diagnostic (self, cr, cell_area, info, state);
+        draw_diagnostic (self, cr, cell_area, info, self->diag_size, state);
 
       /*
        * Now draw the line numbers if we are showing them. Ensure
@@ -1132,6 +1165,7 @@ get_icon_surface (IdeOmniGutterRenderer *self,
   g_assert (IDE_IS_OMNI_GUTTER_RENDERER (self));
   g_assert (GTK_IS_WIDGET (widget));
   g_assert (icon_name != NULL);
+  g_assert (size > 0);
 
   /*
    * This deals with loading a given icon by icon name and trying to
@@ -1203,13 +1237,13 @@ ide_omni_gutter_renderer_reload_icons (IdeOmniGutterRenderer *self)
   if (view == NULL)
     return;
 
-  self->note_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-information-symbolic", 
DIAGNOSTICS_SIZE, FALSE);
-  self->warning_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-warning-symbolic", 
DIAGNOSTICS_SIZE, FALSE);
-  self->error_surface = get_icon_surface (self, GTK_WIDGET (view), "process-stop-symbolic", 
DIAGNOSTICS_SIZE, FALSE);
+  self->note_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-information-symbolic", 
self->diag_size, FALSE);
+  self->warning_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-warning-symbolic", 
self->diag_size, FALSE);
+  self->error_surface = get_icon_surface (self, GTK_WIDGET (view), "process-stop-symbolic", self->diag_size, 
FALSE);
 
-  self->note_selected_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-information-symbolic", 
DIAGNOSTICS_SIZE, TRUE);
-  self->warning_selected_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-warning-symbolic", 
DIAGNOSTICS_SIZE, TRUE);
-  self->error_selected_surface = get_icon_surface (self, GTK_WIDGET (view), "process-stop-symbolic", 
DIAGNOSTICS_SIZE, TRUE);
+  self->note_selected_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-information-symbolic", 
self->diag_size, TRUE);
+  self->warning_selected_surface = get_icon_surface (self, GTK_WIDGET (view), "dialog-warning-symbolic", 
self->diag_size, TRUE);
+  self->error_selected_surface = get_icon_surface (self, GTK_WIDGET (view), "process-stop-symbolic", 
self->diag_size, TRUE);
 }
 
 static void
@@ -1253,8 +1287,8 @@ ide_omni_gutter_renderer_reload (IdeOmniGutterRenderer *self)
   g_set_object (&self->breakpoints, breakpoints);
 
   /* Reload icons and then recalcuate our physical size */
-  ide_omni_gutter_renderer_reload_icons (self);
   ide_omni_gutter_renderer_recalculate_size (self);
+  ide_omni_gutter_renderer_reload_icons (self);
 }
 
 static void