Don't autoscroll right if we are moving left, and vice versa; should fix #4676.

git-svn-id: svn://localhost/ardour2/branches/3.0@11393 d708f5d6-7413-0410-9779-e7cbd77b26cf

5 files changed, 18 insertions, 9 deletions

diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 2bf8fa8052..d9f3669730 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -440,7 +440,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 		return _drags;
 	}
 
-	void maybe_autoscroll (bool, bool);
+	void maybe_autoscroll (bool, bool, bool, bool);
 
 	Gdk::Cursor* get_canvas_cursor () const { return current_canvas_cursor; }
 	void set_canvas_cursor (Gdk::Cursor*, bool save=false);
diff --git a/gtk2_ardour/editor_canvas.cc b/gtk2_ardour/editor_canvas.cc
index 6da76503a7..9a990b4dc3 100644
--- a/gtk2_ardour/editor_canvas.cc
+++ b/gtk2_ardour/editor_canvas.cc
@@ -491,8 +491,15 @@ Editor::autoscroll_fudge_threshold () const
 	return current_page_frames() / 6;
 }
 
+/** @param allow_horiz true to allow horizontal autoscroll, otherwise false.
+ *  @param allow_vert true to allow vertical autoscroll, otherwise false.
+ *  @param moving_left true if we are moving left, so we only want to autoscroll on the left of the canvas,
+ *  otherwise false, so we only want to autoscroll on the right of the canvas.
+ *  @param moving_up true if we are moving up, so we only want to autoscroll at the top of the canvas,
+ *  otherwise false, so we only want to autoscroll at the bottom of the canvas.
+ */
 void
-Editor::maybe_autoscroll (bool allow_horiz, bool allow_vert)
+Editor::maybe_autoscroll (bool allow_horiz, bool allow_vert, bool moving_left, bool moving_up)
 {
 	bool startit = false;
 
@@ -522,10 +529,10 @@ Editor::maybe_autoscroll (bool allow_horiz, bool allow_vert)
 
 	autoscroll_y = 0;
 	autoscroll_x = 0;
-	if (ty < canvas_timebars_vsize && allow_vert) {
+	if (ty < canvas_timebars_vsize && moving_up && allow_vert) {
 		autoscroll_y = -1;
 		startit = true;
-	} else if (ty > _canvas_height && allow_vert) {
+	} else if (ty > _canvas_height && !moving_up && allow_vert) {
 		autoscroll_y = 1;
 		startit = true;
 	}
@@ -536,12 +543,12 @@ Editor::maybe_autoscroll (bool allow_horiz, bool allow_vert)
 	}
 
 	if (_drags->current_pointer_frame() > rightmost_frame && allow_horiz) {
-		if (rightmost_frame < max_framepos) {
+		if (rightmost_frame < max_framepos && !moving_left) {
 			autoscroll_x = 1;
 			startit = true;
 		}
 	} else if (_drags->current_pointer_frame() < leftmost_frame && allow_horiz) {
-		if (leftmost_frame > 0) {
+		if (leftmost_frame > 0 && moving_left) {
 			autoscroll_x = -1;
 			startit = true;
 		}
diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index 582ddeb1fc..380482b703 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -331,7 +331,9 @@ Drag::motion_handler (GdkEvent* event, bool from_autoscroll)
 
 		if (event->motion.state & Gdk::BUTTON1_MASK || event->motion.state & Gdk::BUTTON2_MASK) {
 			if (!from_autoscroll) {
-				_editor->maybe_autoscroll (true, allow_vertical_autoscroll ());
+				bool const moving_left = _drags->current_pointer_x() < _last_pointer_x;
+				bool const moving_up = _drags->current_pointer_y() < _last_pointer_y;
+				_editor->maybe_autoscroll (true, allow_vertical_autoscroll (), moving_left, moving_up);
 			}
 
 			motion (event, _move_threshold_passed != old_move_threshold_passed);
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index 9e4b9884de..c0c32a9bec 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -382,7 +382,7 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible {
 	virtual Gtkmm2ext::TearOff* tools_tearoff () const = 0;
 
 	virtual DragManager* drags () const = 0;
-	virtual void maybe_autoscroll (bool, bool) = 0;
+	virtual void maybe_autoscroll (bool, bool, bool, bool) = 0;
 	virtual void stop_canvas_autoscroll () = 0;
 
 	virtual MouseCursors const * cursors () const = 0;
diff --git a/gtk2_ardour/time_axis_view.cc b/gtk2_ardour/time_axis_view.cc
index 79f425f32f..60d19ad6d4 100644
--- a/gtk2_ardour/time_axis_view.cc
+++ b/gtk2_ardour/time_axis_view.cc
@@ -380,7 +380,7 @@ TimeAxisView::controls_ebox_motion (GdkEventMotion* ev)
 		controls_ebox.translate_coordinates (*control_parent, ev->x, ev->y, tx, ty);
 		ev->y = ty - _editor.get_trackview_group_vertical_offset();
 		_editor.drags()->motion_handler ((GdkEvent *) ev, false);
-		_editor.maybe_autoscroll (false, true);
+		_editor.maybe_autoscroll (false, true, false, ev->y_root < _resize_drag_start);
 
 		/* now do the actual TAV resize */
                 int32_t const delta = (int32_t) floor (ev->y_root - _resize_drag_start);