[evolution] Bug 782210 - Divide message list and preview panel size proportionally

[Milan Crha <mcrha src gnome org>]

commit a58c339def89c507422cd442f73c0878e5bcd1dc
Author: Milan Crha <mcrha redhat com>
Date:   Thu Jun 8 08:48:02 2017 +0200

    Bug 782210 - Divide message list and preview panel size proportionally

 src/e-util/e-paned.c         |  108 +++++++++++++++++++++++++++++++++---------
 src/mail/e-mail-paned-view.c |    1 +
 2 files changed, 87 insertions(+), 22 deletions(-)
---
diff --git a/src/e-util/e-paned.c b/src/e-util/e-paned.c
index 300293a..7c158fb 100644
--- a/src/e-util/e-paned.c
+++ b/src/e-util/e-paned.c
@@ -104,20 +104,15 @@ paned_notify_orientation_cb (EPaned *paned)
 }
 
 static void
-paned_notify_position_cb (EPaned *paned)
+paned_recalc_positions (EPaned *paned,
+                       gboolean with_proportion)
 {
        GtkAllocation allocation;
-       GtkOrientable *orientable;
        GtkOrientation orientation;
        gdouble proportion;
        gint position;
 
-       /* If a sync has already been requested, do nothing. */
-       if (paned->priv->sync_request != SYNC_REQUEST_NONE)
-               return;
-
-       orientable = GTK_ORIENTABLE (paned);
-       orientation = gtk_orientable_get_orientation (orientable);
+       orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (paned));
 
        gtk_widget_get_allocation (GTK_WIDGET (paned), &allocation);
        position = gtk_paned_get_position (GTK_PANED (paned));
@@ -128,18 +123,38 @@ paned_notify_position_cb (EPaned *paned)
                position = MAX (0, allocation.width - position);
                proportion = (gdouble) position / allocation.width;
 
-               paned->priv->hposition = position;
-               g_object_notify (G_OBJECT (paned), "hposition");
+               if (paned->priv->hposition != position) {
+                       paned->priv->hposition = position;
+                       g_object_notify (G_OBJECT (paned), "hposition");
+               }
        } else {
                position = MAX (0, allocation.height - position);
                proportion = (gdouble) position / allocation.height;
 
-               paned->priv->vposition = position;
-               g_object_notify (G_OBJECT (paned), "vposition");
+               if (paned->priv->vposition != position) {
+                       paned->priv->vposition = position;
+                       g_object_notify (G_OBJECT (paned), "vposition");
+               }
        }
 
-       paned->priv->proportion = proportion;
-       g_object_notify (G_OBJECT (paned), "proportion");
+       if (with_proportion && paned->priv->proportion != proportion) {
+               paned->priv->proportion = proportion;
+               g_object_notify (G_OBJECT (paned), "proportion");
+       }
+
+       g_object_thaw_notify (G_OBJECT (paned));
+}
+
+static void
+paned_notify_position_cb (EPaned *paned)
+{
+       /* If a sync has already been requested, do nothing. */
+       if (paned->priv->sync_request != SYNC_REQUEST_NONE)
+               return;
+
+       g_object_freeze_notify (G_OBJECT (paned));
+
+       paned_recalc_positions (paned, TRUE);
 
        if (e_paned_get_fixed_resize (paned))
                paned->priv->sync_request = SYNC_REQUEST_POSITION;
@@ -258,19 +273,32 @@ paned_size_allocate (GtkWidget *widget,
        EPaned *paned = E_PANED (widget);
        GtkOrientable *orientable;
        GtkOrientation orientation;
-       gdouble proportion;
+       gdouble proportion, old_proportion = -1.0;
        gint allocated;
-       gint position;
+       gint position, min_position = -1, max_position = -1, clamp_position;
+       gboolean corrected_portion = FALSE;
+
+       if (!e_paned_get_fixed_resize (paned))
+               old_proportion = e_paned_get_proportion (paned);
 
        /* Chain up to parent's size_allocate() method. */
-       GTK_WIDGET_CLASS (e_paned_parent_class)->
-               size_allocate (widget, allocation);
+       GTK_WIDGET_CLASS (e_paned_parent_class)->size_allocate (widget, allocation);
 
        if (!paned->priv->toplevel_ready)
                return;
 
-       if (paned->priv->sync_request == SYNC_REQUEST_NONE)
+       if (paned->priv->sync_request == SYNC_REQUEST_PROPORTION &&
+           old_proportion != e_paned_get_proportion (paned) && old_proportion > 0.0) {
+               paned->priv->proportion = old_proportion;
+               g_object_notify (G_OBJECT (paned), "proportion");
+
+               corrected_portion = TRUE;
+       }
+
+       if (paned->priv->sync_request == SYNC_REQUEST_NONE) {
+               paned_recalc_positions (paned, FALSE);
                return;
+       }
 
        orientable = GTK_ORIENTABLE (paned);
        orientation = gtk_orientable_get_orientation (orientable);
@@ -285,12 +313,48 @@ paned_size_allocate (GtkWidget *widget,
 
        proportion = e_paned_get_proportion (paned);
 
-       if (paned->priv->sync_request == SYNC_REQUEST_POSITION)
+       if (paned->priv->sync_request == SYNC_REQUEST_POSITION) {
                position = MAX (0, allocated - position);
-       else
+
+               if (!e_paned_get_fixed_resize (paned) && allocated > 0) {
+                       proportion = 1.0 - ((gdouble) position / allocated);
+                       paned->priv->proportion = proportion;
+                       g_object_notify (G_OBJECT (paned), "proportion");
+               }
+       } else {
                position = (1.0 - proportion) * allocated;
+       }
+
+       g_object_get (G_OBJECT (paned),
+               "min-position", &min_position,
+               "max-position", &max_position,
+               NULL);
+
+       clamp_position = position = MAX (0, CLAMP (position, min_position, max_position));
 
-       gtk_paned_set_position (GTK_PANED (paned), position);
+       if (clamp_position != gtk_paned_get_position (GTK_PANED (paned)))
+               gtk_paned_set_position (GTK_PANED (paned), clamp_position);
+
+       if (clamp_position != position && allocated > 0) {
+               proportion = 1.0 - ((gdouble) clamp_position / allocated);
+               paned->priv->proportion = proportion;
+
+               corrected_portion = TRUE;
+       }
+
+       if (corrected_portion) {
+               position = MAX (0, allocated - clamp_position);
+
+               if (position > 0) {
+                       if (orientation == GTK_ORIENTATION_HORIZONTAL) {
+                               paned->priv->hposition = position;
+                               g_object_notify (G_OBJECT (paned), "hposition");
+                       } else {
+                               paned->priv->vposition = position;
+                               g_object_notify (G_OBJECT (paned), "vposition");
+                       }
+               }
+       }
 
        paned->priv->sync_request = SYNC_REQUEST_NONE;
 
diff --git a/src/mail/e-mail-paned-view.c b/src/mail/e-mail-paned-view.c
index b038fe2..cb7e94e 100644
--- a/src/mail/e-mail-paned-view.c
+++ b/src/mail/e-mail-paned-view.c
@@ -710,6 +710,7 @@ mail_paned_view_constructed (GObject *object)
        container = GTK_WIDGET (object);
 
        widget = e_paned_new (GTK_ORIENTATION_VERTICAL);
+       e_paned_set_fixed_resize (E_PANED (widget), FALSE);
        gtk_box_pack_start (GTK_BOX (container), widget, TRUE, TRUE, 0);
        priv->paned = g_object_ref (widget);
        gtk_widget_show (widget);