[libadwaita/wip/exalm/view-switcher-cleanup: 6/16] squeezer: Add switch-threshold-policy

[Alexander Mikhaylenko <alexm src gnome org>]

commit 3826cf69f6fd001e6ed4a11b5a52246bcbc424d7
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Aug 31 15:22:23 2021 +0500

    squeezer: Add switch-threshold-policy
    
    Match leaflet and flap. We'll need this to simplify view switchers.

 src/adw-squeezer.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
 src/adw-squeezer.h |  7 +++++
 2 files changed, 87 insertions(+), 3 deletions(-)
---
diff --git a/src/adw-squeezer.c b/src/adw-squeezer.c
index 18674a7b..acd9b329 100644
--- a/src/adw-squeezer.c
+++ b/src/adw-squeezer.c
@@ -85,6 +85,7 @@ struct _AdwSqueezer
   GList *children;
 
   AdwSqueezerPage *visible_child;
+  AdwFoldThresholdPolicy switch_threshold_policy;
 
   gboolean homogeneous;
 
@@ -116,6 +117,7 @@ struct _AdwSqueezer
 enum  {
   PROP_0,
   PROP_HOMOGENEOUS,
+  PROP_SWITCH_THRESHOLD_POLICY,
   PROP_VISIBLE_CHILD,
   PROP_ALLOW_NONE,
   PROP_TRANSITION_DURATION,
@@ -700,6 +702,9 @@ adw_squeezer_get_property (GObject    *object,
   case PROP_HOMOGENEOUS:
     g_value_set_boolean (value, adw_squeezer_get_homogeneous (self));
     break;
+  case PROP_SWITCH_THRESHOLD_POLICY:
+    g_value_set_enum (value, adw_squeezer_get_switch_threshold_policy (self));
+    break;
   case PROP_VISIBLE_CHILD:
     g_value_set_object (value, adw_squeezer_get_visible_child (self));
     break;
@@ -748,6 +753,9 @@ adw_squeezer_set_property (GObject      *object,
   case PROP_HOMOGENEOUS:
     adw_squeezer_set_homogeneous (self, g_value_get_boolean (value));
     break;
+  case PROP_SWITCH_THRESHOLD_POLICY:
+    adw_squeezer_set_switch_threshold_policy (self, g_value_get_enum (value));
+    break;
   case PROP_ALLOW_NONE:
     adw_squeezer_set_allow_none (self, g_value_get_boolean (value));
     break;
@@ -846,7 +854,7 @@ adw_squeezer_size_allocate (GtkWidget *widget,
 
   for (l = self->children; l; l = l->next) {
     GtkWidget *child = NULL;
-    int child_min;
+    int child_min, child_nat;
     int for_size = -1;
     int compare_size;
 
@@ -877,9 +885,12 @@ adw_squeezer_size_allocate (GtkWidget *widget,
         for_size = height;
 
       gtk_widget_measure (child, self->orientation, for_size,
-                          &child_min, NULL, NULL, NULL);
+                          &child_min, &child_nat, NULL, NULL);
+
+      if (child_min <= compare_size && self->switch_threshold_policy == ADW_FOLD_THRESHOLD_POLICY_MINIMUM)
+        break;
 
-      if (child_min <= compare_size)
+      if (child_nat <= compare_size && self->switch_threshold_policy == ADW_FOLD_THRESHOLD_POLICY_NATURAL)
         break;
     }
   }
@@ -1102,6 +1113,29 @@ adw_squeezer_class_init (AdwSqueezerClass *klass)
                           FALSE,
                           G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
 
+  /**
+   * AdwSqueezer:switch-threshold-policy: (attributes 
org.gtk.Property.get=adw_squeezer_get_switch_threshold_policy 
org.gtk.Property.set=adw_squeezer_set_switch_threshold_policy)
+   *
+   * Determines when the squeezer will switch children.
+   *
+   * If set to `ADW_FOLD_THRESHOLD_POLICY_MINIMUM`, it will only switch when
+   * the visible child cannot fit anymore. With
+   * `ADW_FOLD_THRESHOLD_POLICY_NATURAL`, it will switch as soon as the visible
+   * child doesn't get their natural size.
+   *
+   * This can be useful if you have a long ellipsizing label and want to let it
+   * ellipsize instead of immediately switching.
+   *
+   * Since: 1.0
+   */
+  props[PROP_SWITCH_THRESHOLD_POLICY] =
+    g_param_spec_enum ("switch-threshold-policy",
+                       "Switch Threshold Policy",
+                       "Determines when the leaflet will fold",
+                       ADW_TYPE_FOLD_THRESHOLD_POLICY,
+                       ADW_FOLD_THRESHOLD_POLICY_NATURAL,
+                       G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
   /**
    * AdwSqueezer:visible-child: (attributes org.gtk.Property.get=adw_squeezer_get_visible_child)
    *
@@ -1505,6 +1539,49 @@ adw_squeezer_set_homogeneous (AdwSqueezer *self,
   g_object_notify_by_pspec (G_OBJECT (self), props[PROP_HOMOGENEOUS]);
 }
 
+/**
+ * adw_squeezer_get_switch_threshold_policy: (attributes org.gtk.Method.get_property=fold-threshold-policy)
+ * @self: a `AdwLeaflet`
+ *
+ * Gets the fold threshold policy for @self.
+ *
+ * Since: 1.0
+ */
+AdwFoldThresholdPolicy
+adw_squeezer_get_switch_threshold_policy (AdwSqueezer *self)
+{
+  g_return_val_if_fail (ADW_IS_SQUEEZER (self), ADW_FOLD_THRESHOLD_POLICY_NATURAL);
+
+  return self->switch_threshold_policy;
+}
+
+
+/**
+ * adw_squeezer_set_switch_threshold_policy: (attributes org.gtk.Method.set_property=fold-threshold-policy)
+ * @self: a `AdwSqueezer`
+ * @policy: the policy to use
+ *
+ * Sets the fold threshold policy for @self.
+ *
+ * Since: 1.0
+ */
+void
+adw_squeezer_set_switch_threshold_policy (AdwSqueezer            *self,
+                                          AdwFoldThresholdPolicy  policy)
+{
+  g_return_if_fail (ADW_IS_SQUEEZER (self));
+  g_return_if_fail (policy <= ADW_FOLD_THRESHOLD_POLICY_NATURAL);
+
+  if (self->switch_threshold_policy == policy)
+    return;
+
+  self->switch_threshold_policy = policy;
+
+  gtk_widget_queue_allocate (GTK_WIDGET (self));
+
+  g_object_notify_by_pspec (G_OBJECT (self), props[PROP_SWITCH_THRESHOLD_POLICY]);
+}
+
 /**
  * adw_squeezer_get_allow_none: (attributes org.gtk.Method.get_property=allow-none)
  * @self: a `AdwSqueezer`
diff --git a/src/adw-squeezer.h b/src/adw-squeezer.h
index b4d54e28..6e5b47a2 100644
--- a/src/adw-squeezer.h
+++ b/src/adw-squeezer.h
@@ -14,6 +14,7 @@
 
 #include <gtk/gtk.h>
 #include "adw-enums.h"
+#include "adw-fold-threshold-policy.h"
 
 G_BEGIN_DECLS
 
@@ -61,6 +62,12 @@ ADW_AVAILABLE_IN_ALL
 void     adw_squeezer_set_homogeneous (AdwSqueezer *self,
                                        gboolean     homogeneous);
 
+ADW_AVAILABLE_IN_ALL
+AdwFoldThresholdPolicy adw_squeezer_get_switch_threshold_policy (AdwSqueezer             *self);
+ADW_AVAILABLE_IN_ALL
+void                   adw_squeezer_set_switch_threshold_policy (AdwSqueezer            *self,
+                                                                 AdwFoldThresholdPolicy  policy);
+
 ADW_AVAILABLE_IN_ALL
 gboolean adw_squeezer_get_allow_none (AdwSqueezer *self);
 ADW_AVAILABLE_IN_ALL