From 74796c7a531d71f29c9e603fe33998f19cb96622 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <carl@carlh.net>
Date: Wed, 14 Sep 2011 13:57:20 +0000
Subject: [PATCH] Clamp left hand side zoom drags of the summary (fixes #4317).

git-svn-id: svn://localhost/ardour2/branches/3.0@10075 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 gtk2_ardour/editor_summary.cc | 22 +++++++++++++++++-----
 gtk2_ardour/editor_summary.h  |  8 ++++----
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/gtk2_ardour/editor_summary.cc b/gtk2_ardour/editor_summary.cc
index 1c9ca94021..0c6f1cac58 100644
--- a/gtk2_ardour/editor_summary.cc
+++ b/gtk2_ardour/editor_summary.cc
@@ -608,7 +608,7 @@ EditorSummary::set_editor (double const x, double const y)
  *  x and y parameters are specified in summary coordinates.
  */
 void
-EditorSummary::set_editor (pair<double,double> const & x, double const y)
+EditorSummary::set_editor (pair<double,double> const x, double const y)
 {
 	if (_editor->pending_visual_change.idle_handler_id >= 0) {
 		/* see comment in other set_editor () */
@@ -624,7 +624,7 @@ EditorSummary::set_editor (pair<double,double> const & x, double const y)
  *  x and y parameters are specified in summary coordinates.
  */
 void
-EditorSummary::set_editor (pair<double,double> const & x, pair<double, double> const & y)
+EditorSummary::set_editor (pair<double,double> const x, pair<double, double> const y)
 {
 	if (_editor->pending_visual_change.idle_handler_id >= 0) {
 		/* see comment in other set_editor () */
@@ -640,8 +640,12 @@ EditorSummary::set_editor (pair<double,double> const & x, pair<double, double> c
  *  @param x new x left position in summary coordinates.
  */
 void
-EditorSummary::set_editor_x (double const x)
+EditorSummary::set_editor_x (double x)
 {
+	if (x < 0) {
+		x = 0;
+	}
+	
 	_editor->reset_x_origin (x / _x_scale + _start);
 }
 
@@ -650,8 +654,16 @@ EditorSummary::set_editor_x (double const x)
  *  @param x new x range in summary coordinates.
  */
 void
-EditorSummary::set_editor_x (pair<double, double> const & x)
+EditorSummary::set_editor_x (pair<double, double> x)
 {
+	if (x.first < 0) {
+		x.first = 0;
+	}
+
+	if (x.second < 0) {
+		x.second = 1;
+	}
+	
 	_editor->reset_x_origin (x.first / _x_scale + _start);
 
 	double const nx = (
@@ -694,7 +706,7 @@ EditorSummary::set_editor_y (double const y)
  *  @param y new editor range in summary coodinates.
  */
 void
-EditorSummary::set_editor_y (pair<double, double> const & y)
+EditorSummary::set_editor_y (pair<double, double> const y)
 {
 	/* Compute current height of tracks between y.first and y.second.  We add up
 	   the total height into `total_height' and the height of complete tracks into
diff --git a/gtk2_ardour/editor_summary.h b/gtk2_ardour/editor_summary.h
index 3085f70c49..b465709100 100644
--- a/gtk2_ardour/editor_summary.h
+++ b/gtk2_ardour/editor_summary.h
@@ -70,12 +70,12 @@ private:
 	void render_region (RegionView*, cairo_t*, double) const;
 	void get_editor (std::pair<double, double> *, std::pair<double, double> *) const;
 	void set_editor (double, double);
-	void set_editor (std::pair<double, double> const &, double);
-	void set_editor (std::pair<double, double> const &, std::pair<double, double> const &);
+	void set_editor (std::pair<double, double>, double);
+	void set_editor (std::pair<double, double>, std::pair<double, double>);
 	void set_editor_x (double);
-	void set_editor_x (std::pair<double, double> const &);
+	void set_editor_x (std::pair<double, double>);
 	void set_editor_y (double);
-	void set_editor_y (std::pair<double, double> const &);
+	void set_editor_y (std::pair<double, double>);
 	void playhead_position_changed (framepos_t);
 	double summary_y_to_editor (double) const;
 	double editor_y_to_summary (double) const;