From 4c1fe3bf7a98d375c66dde420443c73d74c15cbf Mon Sep 17 00:00:00 2001
From: Luca Bacci <luca.bacci982@gmail.com>
Date: Fri, 3 Aug 2018 19:25:57 +0200
Subject: [PATCH 12/26] port-to-gtk3: Use draw signal in the partition info
 dialog (#7)

In Gtk2 widgets draw themselves in response to the expose event signal.
In Gtk3 widgets draw themselves in response to the GtkWidget::draw
signal, and the signal handler gets a Cairo context as an argument.

Convert Gtk::DrawingArea rendering code to respond to the
GtkWidget::draw signal.

This commit is specific to the drawing area in the Partition Info
dialog.

Reference:

[1] Migrating from GTK+ 2.x to GTK+ 3 - "The GtkWidget::draw signal":
    https://developer.gnome.org/gtk3/stable/ch26s02.html#id-1.6.3.4.11

Closes #7 - Port to Gtk3
---
 include/Dialog_Partition_Info.h |  2 +-
 src/Dialog_Partition_Info.cc    | 17 +++--------------
 2 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/include/Dialog_Partition_Info.h b/include/Dialog_Partition_Info.h
index 91c731b7..7a5851d8 100644
--- a/include/Dialog_Partition_Info.h
+++ b/include/Dialog_Partition_Info.h
@@ -46,7 +46,7 @@ private:
 	void Display_Info();
 
 	// Signal handler
-	bool drawingarea_on_expose( GdkEventExpose *ev );
+	bool drawingarea_on_draw(const Cairo::RefPtr<Cairo::Context>& cr);
 
 	const Partition & partition;  // (Alias to element in Win_GParted::display_partitions[] vector).
 
diff --git a/src/Dialog_Partition_Info.cc b/src/Dialog_Partition_Info.cc
index f899ab9a..a143458e 100644
--- a/src/Dialog_Partition_Info.cc
+++ b/src/Dialog_Partition_Info.cc
@@ -118,19 +118,8 @@ Dialog_Partition_Info::Dialog_Partition_Info( const Partition & partition ) : pa
 }
 
 
-bool Dialog_Partition_Info::drawingarea_on_expose( GdkEventExpose *ev )
+bool Dialog_Partition_Info::drawingarea_on_draw(const Cairo::RefPtr<Cairo::Context>& cr)
 {
-	Glib::RefPtr<Gdk::Window> window = drawingarea.get_window();
-	if (!window)
-		return true;
-
-	Cairo::RefPtr<Cairo::Context> cr = window->create_cairo_context();
-
-	// Clip to the area indicated by the expose event so that we only redraw
-	// the portion of the window that needs to be redrawn.
-	cr->rectangle(ev->area.x, ev->area.y, ev->area.width, ev->area.height);
-	cr->clip();
-
 	Gdk::Cairo::set_source_color(cr, color_partition);
 	cr->rectangle(0, 0, 400, 60);
 	cr->fill();
@@ -173,8 +162,8 @@ bool Dialog_Partition_Info::drawingarea_on_expose( GdkEventExpose *ev )
 void Dialog_Partition_Info::init_drawingarea() 
 {
 	drawingarea .set_size_request( 400, 60 ) ;
-	drawingarea .signal_expose_event().connect( sigc::mem_fun(*this, &Dialog_Partition_Info::drawingarea_on_expose) ) ;
-	
+	drawingarea.signal_draw().connect(sigc::mem_fun(*this, &Dialog_Partition_Info::drawingarea_on_draw));
+
 	frame = manage( new Gtk::Frame() ) ;
 	frame ->add( drawingarea ) ;
 	
-- 
2.21.0