[gparted] Request natural width in Gtk::ScrolledWindows for Gtk >= 3.22 (!39)

[Mike Fleetwood <mfleetwo src gnome org>]

commit eeffd50531213269680f96a162423a5045711975
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Wed May 1 12:57:38 2019 +0200

    Request natural width in Gtk::ScrolledWindows for Gtk >= 3.22 (!39)
    
    Before Gtk 3.22 GtkScrolledWindow propagated natural size to its
    Children and so on to descendants.  In Gtk 3.22 this was changed to
    always request the minimum size.  This was done because it is believed
    to be a safer default (gives a better behaviour) in case of dynamic
    content inside the scrolled window, that is, content that may change
    allocated size. [1][2][3]
    
    When the scrolled window content is not dynamic the natural size is
    preferable because it gives a better looking layout and without any
    downside.
    
    In the case of GParted content which is not dynamic, so request the
    scrolled windows to allocate children at natural sizes for Gtk >= 3.22.
    
    The benefits of natural size allocation are evident in presence of
    wrapping labels (for example inside the "Partition Info" dialog), that
    with the minimum size request likely end up taking a very small width.
    
    References:
    
    [1] Gtk commit from 2016-08-31:
        GtkScrolledWindow: Make propagation of natural child sizes optional
        https://gitlab.gnome.org/GNOME/gtk/commit/0984d1622d022bf67207f985f7842b6299818e20
        "Making propagation of child natural sizes mandatory (or default,
        even) was evidently a mistake as this causes dynamic content in a
        scrolled window to resize it's parent when the scrolled window is
        competing for space with an adjacent widget."
    
    [2] Gtk 3.22 Reference Documentation -
        gtk_scrolled_window_set_propagate_natural_width
        
https://developer.gnome.org/gtk3/3.22/GtkScrolledWindow.html#gtk-scrolled-window-set-propagate-natural-width
    
    [3] Gtkmm 3.24 Gtk::ScrolledWindow Class Reference,
        set_propagate_natural_width() method
        
https://developer.gnome.org/gtkmm/3.24/classGtk_1_1ScrolledWindow.html#a2d4cb945688ecb8739efd70b18742779
    
    [4] Gtkmm 3.21.6 NEWS
        https://gitlab.gnome.org/GNOME/gtkmm/blob/3.21.6/NEWS
        "ScrolledWindow: Added get/set_propagate_natural_height/width() and
        the properties."
    
    Closes !39 - Always request natural size inside Gtk::ScrolledWindow

 configure.ac                 | 11 +++++++++++
 src/Dialog_Partition_Info.cc |  3 +++
 src/Win_GParted.cc           |  8 +++++++-
 3 files changed, 21 insertions(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index 4016c715..63fd222e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -242,6 +242,17 @@ if test "x$need_cxx_compile_stdcxx_11" = xyes; then
 fi
 
 
+dnl Check for gtkmm >= 3.22 to determine availability of Gtk::ScrolledWindow::set_propagate_natural_width().
+AC_MSG_CHECKING([for Gtk::ScrolledWindow::set_propagate_natural_width() method])
+PKG_CHECK_EXISTS(
+       [gtkmm-3.0 >= 3.22.0],
+       [AC_DEFINE([HAVE_SET_PROPAGATE_NATURAL_WIDTH], 1,
+                  [Define to 1 if gtkmm provides Gtk::ScrolledWindow::set_propagate_natural_width() method.])
+        AC_MSG_RESULT([yes])
+       ],
+       [AC_MSG_RESULT([no])]
+)
+
 
 dnl Definitions for building of and with gtest.  Gets flags for pthread via earlier
 dnl gthread package check.
diff --git a/src/Dialog_Partition_Info.cc b/src/Dialog_Partition_Info.cc
index af13e702..68e831d7 100644
--- a/src/Dialog_Partition_Info.cc
+++ b/src/Dialog_Partition_Info.cc
@@ -52,6 +52,9 @@ Dialog_Partition_Info::Dialog_Partition_Info( const Partition & partition ) : pa
        info_msg_vbox.set_orientation(Gtk::ORIENTATION_VERTICAL);
        info_msg_vbox .set_border_width( 6 ) ;
        info_scrolled .set_policy( Gtk::POLICY_NEVER, Gtk::POLICY_AUTOMATIC ) ;
+#if HAVE_SET_PROPAGATE_NATURAL_WIDTH
+       info_scrolled.set_propagate_natural_width(true);
+#endif
        info_scrolled .add( info_msg_vbox ) ;
        //  As Gtk::Box widget info_msg_vbox doesn't have a native scrolling capability a
        //  Gtk::Viewport is automatically created to contain it when it is added to the
diff --git a/src/Win_GParted.cc b/src/Win_GParted.cc
index 71d18553..4f006b85 100644
--- a/src/Win_GParted.cc
+++ b/src/Win_GParted.cc
@@ -658,6 +658,9 @@ void Win_GParted::init_hpaned_main()
        scrollwindow = manage( new Gtk::ScrolledWindow() ) ;
        scrollwindow ->set_shadow_type( Gtk::SHADOW_ETCHED_IN );
        scrollwindow ->set_policy( Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC );
+#if HAVE_SET_PROPAGATE_NATURAL_WIDTH
+       scrollwindow->set_propagate_natural_width(true);
+#endif
 
        hpaned_main .pack1( *scrollwindow, true, true );
        scrollwindow ->add( vbox_info );
@@ -666,7 +669,10 @@ void Win_GParted::init_hpaned_main()
        scrollwindow = manage( new Gtk::ScrolledWindow() ) ;
        scrollwindow ->set_shadow_type( Gtk::SHADOW_ETCHED_IN );
        scrollwindow ->set_policy( Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC );
-       
+#if HAVE_SET_PROPAGATE_NATURAL_WIDTH
+       scrollwindow->set_propagate_natural_width(true);
+#endif
+
        //connect signals and add treeview_detail
        treeview_detail .signal_partition_selected .connect( sigc::mem_fun( this, 
&Win_GParted::on_partition_selected ) );
        treeview_detail .signal_partition_activated .connect( sigc::mem_fun( this, 
&Win_GParted::on_partition_activated ) );