[gnome-builder] libide: add basic scroll movements

[Christian Hergert <chergert src gnome org>]

commit f798800518ccb2e4b05cff6fe893433ef70e71c6
Author: Christian Hergert <christian hergert me>
Date:   Wed Mar 4 02:30:27 2015 -0800

    libide: add basic scroll movements

 data/keybindings/vim.css           |   13 ++++++++++++
 libide/ide-source-view-movements.c |   37 ++++++++++++++++++++++++++++++++++++
 libide/ide-source-view.h           |    7 ++++++
 3 files changed, 57 insertions(+), 0 deletions(-)
---
diff --git a/data/keybindings/vim.css b/data/keybindings/vim.css
index 2a2ccdb..c24476d 100644
--- a/data/keybindings/vim.css
+++ b/data/keybindings/vim.css
@@ -60,6 +60,7 @@
   /* screen movements, keeping cursor locked to visible region */
   bind "<ctrl>e" { "movement" (screen-up, 0) };
   bind "<ctrl>y" { "movement" (screen-down, 0) };
+  bind "z" { "set-mode" ("vim-normal-z", transient) };
 
   /* move by paragraph */
   bind "bracketleft" { "movement" (previous-paragraph, 0) };
@@ -113,6 +114,13 @@
   bind "<ctrl>v" { "set-mode" ("vim-visual-block") };
 }
 
+ binding-set builder-vim-source-view-normal-z
+{
+  bind "z" { "movement" (scroll-screen-center, 0) };
+  bind "t" { "movement" (scroll-screen-top, 0) };
+  bind "b" { "movement" (scroll-screen-bottom, 0) };
+}
+
 @binding-set builder-vim-source-view-normal-y
 {
   bind "y" { "save-cursor" ()
@@ -168,6 +176,11 @@ IdeSourceViewMode.vim-normal-y {
                     builder-vim-source-view-normal-y;
 }
 
+IdeSourceViewMode.vim-normal-z {
+  gtk-key-bindings: builder-vim-source-view,
+                    builder-vim-source-view-normal-z;
+}
+
 IdeSourceViewMode.vim-insert {
   gtk-key-bindings: builder-vim-source-view, builder-vim-source-view-insert;
 }
diff --git a/libide/ide-source-view-movements.c b/libide/ide-source-view-movements.c
index a3e1431..ed389d2 100644
--- a/libide/ide-source-view-movements.c
+++ b/libide/ide-source-view-movements.c
@@ -491,6 +491,37 @@ ide_source_view_movements_match_special (IdeSourceView         *self,
     ide_source_view_movements_select_range (self, &insert, &selection, extend_selection);
 }
 
+static void
+ide_source_view_movements_scroll_center (IdeSourceView         *self,
+                                         IdeSourceViewMovement  movement,
+                                         gboolean               extend_selection,
+                                         gint                   param)
+{
+  GtkTextView *text_view = (GtkTextView *)self;
+  GtkTextIter insert;
+  GtkTextIter selection;
+
+  ide_source_view_movements_get_selection (self, &insert, &selection);
+
+  switch ((int)movement)
+    {
+    case IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_BOTTOM:
+      gtk_text_view_scroll_to_iter (text_view, &insert, 0.0, TRUE, 0.5, 1.0);
+      break;
+
+    case IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_TOP:
+      gtk_text_view_scroll_to_iter (text_view, &insert, 0.0, TRUE, 0.5, 0.0);
+      break;
+
+    case IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_CENTER:
+      gtk_text_view_scroll_to_iter (text_view, &insert, 0.0, TRUE, 0.5, 0.5);
+      break;
+
+    default:
+      break;
+    }
+}
+
 void
 _ide_source_view_apply_movement (IdeSourceView         *self,
                                  IdeSourceViewMovement  movement,
@@ -621,6 +652,12 @@ _ide_source_view_apply_movement (IdeSourceView         *self,
       ide_source_view_movements_match_special (self, movement, extend_selection, param);
       break;
 
+    case IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_TOP:
+    case IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_CENTER:
+    case IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_BOTTOM:
+      ide_source_view_movements_scroll_center (self, movement, extend_selection, param);
+      break;
+
     default:
       g_return_if_reached ();
     }
diff --git a/libide/ide-source-view.h b/libide/ide-source-view.h
index 771be8c..d7a80d7 100644
--- a/libide/ide-source-view.h
+++ b/libide/ide-source-view.h
@@ -89,6 +89,9 @@ typedef enum
  * @IDE_SOURCE_VIEW_MOVEMENT_SCREEN_MIDDLE: move to the middle of the screen.
  * @IDE_SOURCE_VIEW_MOVEMENT_SCREEN_BOTTOM: move to the bottom of the screen.
  * @IDE_SOURCE_VIEW_MOVEMENT_MATCH_SPECIAL: move to match of brace, bracket, comment.
+ * @IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_TOP: scroll until insert cursor is at screen top.
+ * @IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_CENTER: scroll until insert cursor is at screen center.
+ * @IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_BOTTOM: scroll until insert cursor is at screen bottom.
  *
  * The type of movement.
  *
@@ -138,6 +141,10 @@ typedef enum
   IDE_SOURCE_VIEW_MOVEMENT_SCREEN_BOTTOM,
 
   IDE_SOURCE_VIEW_MOVEMENT_MATCH_SPECIAL,
+
+  IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_TOP,
+  IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_CENTER,
+  IDE_SOURCE_VIEW_MOVEMENT_SCROLL_SCREEN_BOTTOM,
 } IdeSourceViewMovement;
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (IdeSourceView, g_object_unref)