[gnome-builder/wip/libide] libide: override GtkTextView::paste_clipboard() to add line paste mode

[Christian Hergert <chergert src gnome org>]

commit c43420d4500b3f26214c7c7857c39fb81b459cdf
Author: Christian Hergert <christian hergert me>
Date:   Thu Mar 5 14:07:13 2015 -0800

    libide: override GtkTextView::paste_clipboard() to add line paste mode
    
    This helps when pasting entire lines (text followed by \n). We treat the
    paste as an entire line paste rather than simply pasting in position.
    
    We might need to add some special hooks for whether or not we want this,
    but in general I think it is pretty useful.
    
    To support vim mode's P, we'll need to add a "paste-clipboard-before"
    anyway, so not the end of the word if we want to split this out.

 libide/ide-source-view.c |   80 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 80 insertions(+), 0 deletions(-)
---
diff --git a/libide/ide-source-view.c b/libide/ide-source-view.c
index 3165799..de35dbf 100644
--- a/libide/ide-source-view.c
+++ b/libide/ide-source-view.c
@@ -1747,6 +1747,83 @@ ide_source_view_real_jump (IdeSourceView     *self,
 }
 
 static void
+ide_source_view_real_paste_clipboard (GtkTextView *text_view)
+{
+  IdeSourceView *self = (IdeSourceView *)text_view;
+  g_autofree gchar *text = NULL;
+  GtkClipboard *clipboard;
+  GtkTextBuffer *buffer;
+
+  /*
+   * NOTE:
+   *
+   * In this function, we try to improve how pasteing works in GtkTextView. There are some
+   * semenatics that make things easier by tracking the paste of an entire line verses small
+   * snippets of text.
+   *
+   * Basically, we are implementing something close to Vim. However that is not a strict
+   * requirement, just what we are starting with. In fact, the rest of the handling to be like vim
+   * is handled within vim.css (for example, what character to leave the insert mark on).
+   */
+
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  buffer = gtk_text_view_get_buffer (text_view);
+
+  clipboard = gtk_widget_get_clipboard (GTK_WIDGET (self), GDK_SELECTION_CLIPBOARD);
+  text = gtk_clipboard_wait_for_text (clipboard);
+
+  gtk_text_buffer_begin_user_action (buffer);
+
+  /*
+   * If we are pasting an entire line, we don't want to paste it at the current location. We want
+   * to insert a new line after the current line, and then paste it there (so move the insert mark
+   * first).
+   */
+  if (text && g_str_has_suffix (text, "\n"))
+    {
+      g_autofree gchar *trimmed = NULL;
+
+      /*
+       * WORKAROUND:
+       *
+       * This is a hack so that we can continue to use the paste code from within GtkTextBuffer.
+       *
+       * We needed to keep the trailing \n in the text so that we know when we are selecting whole
+       * lines. We also need to insert a new line manually based on the context. Furthermore, we
+       * need to remove the trailing line since we already added one.
+       *
+       * Terribly annoying, but the result is something that feels very nice, similar to Vim.
+       */
+      trimmed = g_strndup (text, strlen (text) - 1);
+      _ide_source_view_apply_movement (self, IDE_SOURCE_VIEW_MOVEMENT_LAST_CHAR, FALSE, 0);
+      g_signal_emit_by_name (self, "insert-at-cursor", "\n");
+      gtk_clipboard_set_text (clipboard, trimmed, -1);
+      GTK_TEXT_VIEW_CLASS (ide_source_view_parent_class)->paste_clipboard (text_view);
+      gtk_clipboard_set_text (clipboard, text, -1);
+    }
+  else
+    {
+#if 0
+      /*
+       * TODO:
+       *
+       * This is more important once we get block mode rendering for characters in place.
+       *
+       * By default, GtkTextBuffer will paste at our current position.  While VIM will paste after
+       * the current position. Let's advance the buffer a single character on the current line if
+       * possible. We switch to insert mode so that we can move past the last character in the
+       * buffer. Possibly should consider an alternate design for this.
+       */
+      _ide_source_view_apply_movement (self, IDE_SOURCE_VIEW_MOVEMENT_NEXT_CHAR, FALSE, 0);
+#endif
+      GTK_TEXT_VIEW_CLASS (ide_source_view_parent_class)->paste_clipboard (text_view);
+    }
+
+  gtk_text_buffer_end_user_action (buffer);
+}
+
+static void
 ide_source_view_real_selection_theatric (IdeSourceView         *self,
                                          IdeSourceViewTheatric  theatric)
 {
@@ -2111,6 +2188,7 @@ ide_source_view_class_init (IdeSourceViewClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GtkTextViewClass *text_view_class = GTK_TEXT_VIEW_CLASS (klass);
 
   object_class->constructed = ide_source_view_constructed;
   object_class->dispose = ide_source_view_dispose;
@@ -2121,6 +2199,8 @@ ide_source_view_class_init (IdeSourceViewClass *klass)
   widget_class->key_press_event = ide_source_view_key_press_event;
   widget_class->query_tooltip = ide_source_view_query_tooltip;
 
+  text_view_class->paste_clipboard = ide_source_view_real_paste_clipboard;
+
   klass->action = ide_source_view_real_action;
   klass->change_case = ide_source_view_real_change_case;
   klass->clear_selection = ide_source_view_real_clear_selection;