From 5da8d7521a600a5924fd10c52db21a367db72f97 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Tue, 20 Oct 2020 21:10:49 +0200
Subject: [PATCH] Try to improve splitter behaviour when shrinking and then
 enlarging the main window (#1839).

---
 src/wx/content_panel.cc | 19 ++++++++++++++++++-
 src/wx/content_panel.h  |  6 ++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/wx/content_panel.cc b/src/wx/content_panel.cc
index 8b6b02316..9ec44a9f2 100644
--- a/src/wx/content_panel.cc
+++ b/src/wx/content_panel.cc
@@ -803,11 +803,14 @@ ContentPanel::panels () const
 
 LimitedSplitter::LimitedSplitter (wxWindow* parent)
 	: wxSplitterWindow (parent, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxSP_NOBORDER | wxSP_3DSASH | wxSP_LIVE_UPDATE)
+	, _top_panel_minimum_size (350)
 {
 	/* This value doesn't really mean much but we just want to stop double-click on the
 	   divider from shrinking the bottom panel (#1601).
 	*/
 	SetMinimumPaneSize (64);
+
+	Bind (wxEVT_SIZE, boost::bind(&LimitedSplitter::sized, this, _1));
 }
 
 
@@ -820,10 +823,24 @@ LimitedSplitter::first_shown (wxWindow* top, wxWindow* bottom)
 		/* This is a hack to try and make the content notebook a sensible size; large on big displays but small
 		   enough on small displays to leave space for the content area.
 		   */
-		SplitHorizontally (top, bottom, screen.height > 800 ? -600 : -150);
+		SplitHorizontally (top, bottom, screen.height > 800 ? -600 : -_top_panel_minimum_size);
 	} else {
 		/* Fallback for when GetFromWindow fails for reasons that aren't clear */
 		SplitHorizontally (top, bottom, -600);
 	}
 
 }
+
+
+void
+LimitedSplitter::sized (wxSizeEvent& ev)
+{
+	if (_first_shown && GetSize().GetHeight() > _top_panel_minimum_size && GetSashPosition() < _top_panel_minimum_size) {
+		/* The window is now fairly big but the top panel is small; this happens when the DCP-o-matic window
+		 * is shrunk and then made larger again.  Try to set a sensible top panel size in this case (#1839).
+		 */
+		SetSashPosition (_top_panel_minimum_size);
+	}
+
+	ev.Skip ();
+}
diff --git a/src/wx/content_panel.h b/src/wx/content_panel.h
index 52a7e9f3c..df5c58ebd 100644
--- a/src/wx/content_panel.h
+++ b/src/wx/content_panel.h
@@ -54,6 +54,12 @@ public:
 	}
 
 	void first_shown (wxWindow* top, wxWindow* bottom);
+
+private:
+	void sized (wxSizeEvent& ev);
+
+	bool _first_shown;
+	int const _top_panel_minimum_size;
 };
 
 
-- 
2.30.2