[libhandy/wip/exalm/leaflet-transltions: 29/31] stackable-box: Add a way to track child visible progress

[Alexander Mikhaylenko <alexm src gnome org>]

commit b48706a18e1504498e5866afd0a273e8dcb66698
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Fri Jul 31 22:55:44 2020 +0500

    stackable-box: Add a way to track child visible progress
    
    Signed-off-by: Alexander Mikhaylenko <alexm gnome org>

 src/hdy-stackable-box-private.h |  2 ++
 src/hdy-stackable-box.c         | 66 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
---
diff --git a/src/hdy-stackable-box-private.h b/src/hdy-stackable-box-private.h
index 25f5bdbd..d73a87e4 100644
--- a/src/hdy-stackable-box-private.h
+++ b/src/hdy-stackable-box-private.h
@@ -93,6 +93,8 @@ void             hdy_stackable_box_set_child_navigatable (HdyStackableBox *self,
 
 gboolean         hdy_stackable_box_get_child_visible (HdyStackableBox *self,
                                                       GtkWidget       *widget);
+gdouble          hdy_stackable_box_get_child_progress (HdyStackableBox *self,
+                                                       GtkWidget       *widget);
 
 void             hdy_stackable_box_switch_child (HdyStackableBox *self,
                                                  guint            index,
diff --git a/src/hdy-stackable-box.c b/src/hdy-stackable-box.c
index 02d55c80..259d33a4 100644
--- a/src/hdy-stackable-box.c
+++ b/src/hdy-stackable-box.c
@@ -73,6 +73,7 @@ enum {
 
 enum {
   SIGNAL_CHILD_NOTIFY_VISIBLE,
+  SIGNAL_CHILD_NOTIFY_PROGRESS,
   SIGNAL_LAST_SIGNAL,
 };
 
@@ -96,6 +97,7 @@ struct _HdyStackableBoxChildInfo
   GtkRequisition min;
   GtkRequisition nat;
   gboolean visible;
+  gdouble visible_progress;
 };
 
 struct _HdyStackableBox
@@ -344,6 +346,16 @@ set_child_visible (HdyStackableBox          *self,
   g_signal_emit (self, signals[SIGNAL_CHILD_NOTIFY_VISIBLE], 0, widget);
 }
 
+static void
+notify_child_progress (HdyStackableBox          *self,
+                       HdyStackableBoxChildInfo *child_info)
+{
+  if (!child_info)
+    return;
+
+  g_signal_emit (self, signals[SIGNAL_CHILD_NOTIFY_PROGRESS], 0, child_info->widget);
+}
+
 static void
 hdy_stackable_box_child_progress_updated (HdyStackableBox *self)
 {
@@ -355,9 +367,16 @@ hdy_stackable_box_child_progress_updated (HdyStackableBox *self)
   else
     gtk_widget_queue_allocate (GTK_WIDGET (self->container));
 
+  if (self->folded) {
+    notify_child_progress (self, self->visible_child);
+    notify_child_progress (self, self->last_visible_child);
+  }
+
   if (!self->child_transition.is_gesture_active &&
       gtk_progress_tracker_get_state (&self->child_transition.tracker) == GTK_PROGRESS_STATE_AFTER) {
     if (self->child_transition.is_cancelled) {
+      HdyStackableBoxChildInfo *prev_child = self->visible_child;
+
       if (self->last_visible_child != NULL) {
         if (self->folded) {
           set_child_visible (self, self->last_visible_child, TRUE);
@@ -367,6 +386,9 @@ hdy_stackable_box_child_progress_updated (HdyStackableBox *self)
         self->last_visible_child = NULL;
       }
 
+      notify_child_progress (self, self->visible_child);
+      notify_child_progress (self, prev_child);
+
       self->child_transition.is_cancelled = FALSE;
 
       g_object_freeze_notify (G_OBJECT (self));
@@ -636,11 +658,17 @@ static void
 hdy_stackable_box_set_position (HdyStackableBox *self,
                                 gdouble          pos)
 {
+  GList *l;
+
   self->mode_transition.current_pos = pos;
 
   gtk_widget_queue_allocate (GTK_WIDGET (self->container));
 
   g_object_notify_by_pspec (G_OBJECT (self), props[PROP_MODE_TRANSITION_PROGRESS]);
+
+  for (l = self->children; l; l = l->next)
+    if (l->data != self->visible_child)
+      notify_child_progress (self, l->data);
 }
 
 static void
@@ -2973,6 +3001,34 @@ hdy_stackable_box_get_child_visible (HdyStackableBox *self,
   return gtk_widget_get_child_visible (widget);
 }
 
+gdouble
+hdy_stackable_box_get_child_progress (HdyStackableBox *self,
+                                      GtkWidget       *widget)
+{
+  HdyStackableBoxChildInfo *child_info;
+
+  child_info = find_child_info_for_widget (self, widget);
+
+  g_return_val_if_fail (child_info != NULL, 0.0);
+
+  if (self->child_transition.is_gesture_active ||
+      gtk_progress_tracker_get_state (&self->child_transition.tracker) != GTK_PROGRESS_STATE_AFTER) {
+
+    if (child_info == self->visible_child)
+      return self->child_transition.progress;
+
+    if (child_info == self->last_visible_child)
+      return 1 - self->child_transition.progress;
+
+    return 0;
+  }
+
+  if (child_info == self->visible_child)
+    return 1;
+
+  return self->mode_transition.current_pos;
+}
+
 static void
 hdy_stackable_box_class_init (HdyStackableBoxClass *klass)
 {
@@ -3180,6 +3236,16 @@ hdy_stackable_box_class_init (HdyStackableBoxClass *klass)
                   G_TYPE_NONE,
                   1,
                   GTK_TYPE_WIDGET);
+
+  signals[SIGNAL_CHILD_NOTIFY_PROGRESS] =
+    g_signal_new ("child-notify-progress",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE,
+                  1,
+                  GTK_TYPE_WIDGET);
 }
 
 HdyStackableBox *