[gtranslator/font-size] WIP: Font size change support

[Daniel Garcia Moreno <danigm src gnome org>]

commit d4dec9d45f19db6136c6f5d3a71346c784451e7c
Author: Daniel García Moreno <dani danigm net>
Date:   Tue Sep 8 10:10:34 2020 +0200

    WIP: Font size change support

 src/gtr-tab.c  | 52 ++++++++++++++++++++++++++++++++++++++
 src/gtr-tab.ui | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/gtr-view.c | 33 ++++++++++++++++++++++++
 src/gtr-view.h |  4 +++
 4 files changed, 168 insertions(+)
---
diff --git a/src/gtr-tab.c b/src/gtr-tab.c
index 2f864e6b..be680a36 100644
--- a/src/gtr-tab.c
+++ b/src/gtr-tab.c
@@ -119,6 +119,12 @@ typedef struct
   GtkRevealer    *search_revealer;
   GtrSearchBar   *search_bar;
   GtkSearchEntry *search;
+
+  /* Text zoom */
+  GtkWidget *zoom_in;
+  GtkWidget *zoom_original;
+  GtkWidget *zoom_out;
+
 } GtrTabPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (GtrTab, gtr_tab, GTK_TYPE_BOX)
@@ -226,6 +232,42 @@ gtr_page_notify_child_revealed (GtrTab *tab,
 
 //----------------------------------------------------------------//
 
+// TODO: Zoom also *trans_msgstr[MAX_PLURALS];
+static gboolean
+zoom_in (GtkWidget *widget, GtrTab *tab)
+{
+  GtrTabPrivate *priv;
+  GtrView *view;
+
+  priv = gtr_tab_get_instance_private (tab);
+  view = GTR_VIEW (priv->text_msgid);
+  gtr_view_zoom_in (view);
+  return TRUE;
+}
+
+static gboolean
+zoom_original (GtkWidget *widget, GtrTab *tab)
+{
+  GtrTabPrivate *priv;
+  GtrView *view;
+
+  priv = gtr_tab_get_instance_private (tab);
+  view = GTR_VIEW (priv->text_msgid);
+  gtr_view_zoom_original (view);
+  return TRUE;
+}
+
+static gboolean
+zoom_out (GtkWidget *widget, GtrTab *tab)
+{
+  GtrTabPrivate *priv;
+  GtrView *view;
+
+  priv = gtr_tab_get_instance_private (tab);
+  view = GTR_VIEW (priv->text_msgid);
+  gtr_view_zoom_out (view);
+  return TRUE;
+}
 
 static gboolean
 show_hide_revealer (GtkWidget *widget, GdkEvent *ev, GtrTab *tab)
@@ -774,6 +816,13 @@ gtr_tab_init (GtrTab * tab)
 
   g_signal_connect (priv->progress_eventbox, "button-press-event",
                     G_CALLBACK (show_hide_revealer), tab);
+
+  g_signal_connect (priv->zoom_in, "clicked",
+                    G_CALLBACK (zoom_in), tab);
+  g_signal_connect (priv->zoom_original, "clicked",
+                    G_CALLBACK (zoom_original), tab);
+  g_signal_connect (priv->zoom_out, "clicked",
+                    G_CALLBACK (zoom_out), tab);
 }
 
 static void
@@ -959,6 +1008,9 @@ gtr_tab_class_init (GtrTabClass * klass)
   gtk_widget_class_bind_template_child_private (widget_class, GtrTab, overlay);
   gtk_widget_class_bind_template_child_private (widget_class, GtrTab, search_bar);
   gtk_widget_class_bind_template_child_private (widget_class, GtrTab, search_revealer);
+  gtk_widget_class_bind_template_child_private (widget_class, GtrTab, zoom_in);
+  gtk_widget_class_bind_template_child_private (widget_class, GtrTab, zoom_original);
+  gtk_widget_class_bind_template_child_private (widget_class, GtrTab, zoom_out);
   gtk_widget_class_bind_template_callback (widget_class, gtr_page_notify_child_revealed);
   gtk_widget_class_bind_template_callback (widget_class, gtr_page_stop_search);
 
diff --git a/src/gtr-tab.ui b/src/gtr-tab.ui
index 49a144c9..3c222ffb 100644
--- a/src/gtr-tab.ui
+++ b/src/gtr-tab.ui
@@ -110,6 +110,85 @@
                                           </style>
                                        </object>
                                     </child>
+
+                                    <child>
+                                      <object class="GtkButtonBox">
+                                        <property name="visible">True</property>
+                                        <property name="can_focus">False</property>
+                                        <property name="layout_style">start</property>
+                                        <property name="halign">end</property>
+                                        <style>
+                                         <class name="linked"/>
+                                         <class name="horizontal"/>
+                                        </style>
+                                        <child>
+                                          <object class="GtkButton" id="zoom_in">
+                                            <property name="visible">True</property>
+                                            <property name="can_focus">True</property>
+                                            <property name="receives_default">True</property>
+                                            <child>
+                                              <object class="GtkImage">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">False</property>
+                                                <property name="icon_name">zoom-in-symbolic</property>
+                                              </object>
+                                            </child>
+                                          </object>
+                                          <packing>
+                                            <property name="expand">True</property>
+                                            <property name="fill">True</property>
+                                            <property name="position">0</property>
+                                            <property name="non_homogeneous">True</property>
+                                          </packing>
+                                        </child>
+                                        <child>
+                                          <object class="GtkButton" id="zoom_original">
+                                            <property name="visible">True</property>
+                                            <property name="can_focus">True</property>
+                                            <property name="receives_default">True</property>
+                                            <child>
+                                              <object class="GtkImage">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">False</property>
+                                                <property name="icon_name">zoom-original-symbolic</property>
+                                              </object>
+                                            </child>
+                                          </object>
+                                          <packing>
+                                            <property name="expand">True</property>
+                                            <property name="fill">True</property>
+                                            <property name="position">1</property>
+                                            <property name="non_homogeneous">True</property>
+                                          </packing>
+                                        </child>
+                                        <child>
+                                          <object class="GtkButton" id="zoom_out">
+                                            <property name="visible">True</property>
+                                            <property name="can_focus">True</property>
+                                            <property name="receives_default">True</property>
+                                            <child>
+                                              <object class="GtkImage">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">False</property>
+                                                <property name="icon_name">zoom-out-symbolic</property>
+                                              </object>
+                                            </child>
+                                          </object>
+                                          <packing>
+                                            <property name="expand">True</property>
+                                            <property name="fill">True</property>
+                                            <property name="position">2</property>
+                                            <property name="non_homogeneous">True</property>
+                                          </packing>
+                                        </child>
+                                      </object>
+                                      <packing>
+                                        <property name="expand">True</property>
+                                        <property name="fill">True</property>
+                                        <property name="position">4</property>
+                                      </packing>
+                                    </child>
+
                                  </object>
                                  <packing>
                                     <property name="expand">False</property>
diff --git a/src/gtr-view.c b/src/gtr-view.c
index 2c53cfb5..985663e0 100644
--- a/src/gtr-view.c
+++ b/src/gtr-view.c
@@ -91,6 +91,7 @@ typedef struct
   gchar *search_text;
 
   GspellChecker *spell;
+  GtkCssProvider *provider;
 } GtrViewPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (GtrView, gtr_view, GTK_SOURCE_TYPE_VIEW)
@@ -108,6 +109,11 @@ gtr_view_init (GtrView * view)
 
   priv = gtr_view_get_instance_private (view);
 
+  priv->provider = gtk_css_provider_new ();
+  gtk_style_context_add_provider (gtk_widget_get_style_context (GTK_WIDGET (view)),
+                                  GTK_STYLE_PROVIDER (priv->provider),
+                                  GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+
   priv->spell = NULL;
   priv->editor_settings = g_settings_new ("org.gnome.gtranslator.preferences.editor");
   priv->ui_settings = g_settings_new ("org.gnome.gtranslator.preferences.ui");
@@ -160,6 +166,7 @@ gtr_view_dispose (GObject * object)
   g_clear_object (&priv->editor_settings);
   g_clear_object (&priv->ui_settings);
   g_clear_object (&priv->spell);
+  g_object_unref (&priv->provider);
 
   G_OBJECT_CLASS (gtr_view_parent_class)->dispose (object);
 }
@@ -898,3 +905,29 @@ gtr_view_reload_scheme_color (GtrView * view)
 
   gtk_source_buffer_set_style_scheme (buf, scheme);
 }
+
+// TODO: store the font-size in settings
+// TODO: original, use default font-size
+void
+gtr_view_zoom_in (GtrView *view)
+{
+  GtrViewPrivate *priv = gtr_view_get_instance_private (view);
+  const gchar * css = "textview { font-size: 16pt; }";
+  gtk_css_provider_load_from_data (priv->provider, css, -1, NULL);
+}
+
+void
+gtr_view_zoom_original (GtrView *view)
+{
+  GtrViewPrivate *priv = gtr_view_get_instance_private (view);
+  const gchar * css = "textview { }";
+  gtk_css_provider_load_from_data (priv->provider, css, -1, NULL);
+}
+
+void
+gtr_view_zoom_out (GtrView *view)
+{
+  GtrViewPrivate *priv = gtr_view_get_instance_private (view);
+  const gchar * css = "textview { font-size: 8pt; }";
+  gtk_css_provider_load_from_data (priv->provider, css, -1, NULL);
+}
diff --git a/src/gtr-view.h b/src/gtr-view.h
index 87ee0e3d..1d1bdc19 100644
--- a/src/gtr-view.h
+++ b/src/gtr-view.h
@@ -115,6 +115,10 @@ gtr_view_get_type (void)
      void gtr_view_set_language (GtrView *view,
                                  const gchar *lang);
 
+     void gtr_view_zoom_in       (GtrView *view);
+     void gtr_view_zoom_original (GtrView *view);
+     void gtr_view_zoom_out      (GtrView *view);
+
 
 /* Search macros */
 #define GTR_SEARCH_IS_DONT_SET_FLAGS(sflags) ((sflags & GTR_SEARCH_DONT_SET_FLAGS) != 0)