[libgepub/widget-pagination] First attempt of real pagination in the widget

[Daniel Garcia Moreno <danigm src gnome org>]

commit 848d51bb7f3903bbbe8c0fdd2ef0e65fc59bc598
Author: Daniel Garcia Moreno <danigm wadobo com>
Date:   Fri Jul 1 21:39:26 2016 +0200

    First attempt of real pagination in the widget

 libgepub/gepub-widget.c |   99 +++++++++++++++++++++++++++++++++++++++++++++++
 libgepub/gepub-widget.h |    4 ++
 tests/test-gepub.c      |   35 +++++++++++++++--
 3 files changed, 134 insertions(+), 4 deletions(-)
---
diff --git a/libgepub/gepub-widget.c b/libgepub/gepub-widget.c
index 7e7a239..5d5a846 100644
--- a/libgepub/gepub-widget.c
+++ b/libgepub/gepub-widget.c
@@ -26,6 +26,8 @@ struct _GepubWidget {
     WebKitWebView parent;
 
     GepubDoc *doc;
+    gboolean paginate;
+    gint page;
 };
 
 struct _GepubWidgetClass {
@@ -35,6 +37,7 @@ struct _GepubWidgetClass {
 enum {
     PROP_0,
     PROP_DOC,
+    PROP_PAGINATE,
     NUM_PROPS
 };
 
@@ -87,6 +90,9 @@ gepub_widget_set_property (GObject      *object,
     case PROP_DOC:
         gepub_widget_set_doc (widget, g_value_get_object (value));
         break;
+    case PROP_PAGINATE:
+        gepub_widget_set_pagination (widget, g_value_get_boolean (value));
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
@@ -105,6 +111,9 @@ gepub_widget_get_property (GObject    *object,
     case PROP_DOC:
         g_value_set_object (value, gepub_widget_get_doc (widget));
         break;
+    case PROP_PAGINATE:
+        g_value_set_boolean (value, widget->paginate);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
@@ -156,6 +165,13 @@ gepub_widget_class_init (GepubWidgetClass *klass)
                              G_PARAM_READWRITE |
                              G_PARAM_STATIC_STRINGS);
 
+    properties[PROP_PAGINATE] =
+        g_param_spec_boolean ("paginate",
+                              "paginate",
+                              "If the widget should paginate",
+                              FALSE,
+                              G_PARAM_READWRITE);
+
     g_object_class_install_properties (object_class, NUM_PROPS, properties);
 }
 
@@ -184,6 +200,48 @@ gepub_widget_get_doc (GepubWidget *widget)
 }
 
 static void
+paginate_cb (WebKitWebView  *web_view,
+             WebKitLoadEvent load_event,
+             gpointer        user_data)
+{
+
+    GepubWidget *widget = GEPUB_WIDGET (web_view);
+
+    if (load_event == WEBKIT_LOAD_FINISHED) {
+        const gchar *script = "function initialize() { "
+                                  "var d = document.querySelector('body');"
+                                  "var ourH = window.innerHeight - 40; "
+                                  "var ourW = window.innerWidth - 20; "
+                                  "var fullH = d.offsetHeight; "
+                                  "var pageCount = Math.floor(fullH/ourH)+1;"
+                                  "var newW = pageCount * ourW; "
+                                  "d.style.height = ourH+'px';"
+                                  "d.style.width = newW+'px';"
+                                  "d.style.WebkitColumnCount = pageCount;"
+                                  "d.style.WebkitColumnGap = '20px';"
+                                  "d.style.overflow = 'hidden';"
+                                  "window.currentPage = 0; "
+                              "};"
+                              "function next() { "
+                                  "var ourW = window.innerWidth - 10; "
+                                  "window.currentPage += 1; "
+                                  "window.scroll(ourW * window.currentPage, 0); "
+                              "};"
+                              "function prev() { "
+                                  "var ourW = window.innerWidth - 10; "
+                                  "window.currentPage -= 1; "
+                                  "window.scroll(ourW * window.currentPage, 0); "
+                              "};"
+                              "initialize();";
+
+        if (widget->paginate) {
+            webkit_web_view_run_javascript(web_view, "document.querySelector('body').style.margin = 
'20px';", NULL, NULL, NULL);
+            webkit_web_view_run_javascript(web_view, script, NULL, NULL, NULL);
+        }
+    }
+}
+
+static void
 reload_current_chapter (GepubWidget *widget)
 {
     GBytes *current;
@@ -194,6 +252,8 @@ reload_current_chapter (GepubWidget *widget)
                                 gepub_doc_get_current_mime (widget->doc),
                                 "UTF-8", NULL);
 
+    g_signal_connect (widget, "load-changed", G_CALLBACK (paginate_cb), NULL);
+
     g_bytes_unref (current);
 }
 
@@ -228,3 +288,42 @@ gepub_widget_set_doc (GepubWidget *widget,
 
     g_object_notify_by_pspec (G_OBJECT (widget), properties[PROP_DOC]);
 }
+
+/**
+ * gepub_widget_set_pagination:
+ * @widget: a #GepubWidget
+ * @p: true if the widget should paginate
+ *
+ * Enable or disable pagination
+ */
+void
+gepub_widget_set_pagination (GepubWidget *widget,
+                             gboolean p)
+{
+    widget->paginate = p;
+    reload_current_chapter (widget);
+}
+
+/**
+ * gepub_widget_page_next:
+ * @widget: a #GepubWidget
+ *
+ * Change the page to the next
+ */
+void
+gepub_widget_page_next (GepubWidget *widget)
+{
+    webkit_web_view_run_javascript(WEBKIT_WEB_VIEW (widget), "next();", NULL, NULL, NULL);
+}
+
+/**
+ * gepub_widget_page_prev:
+ * @widget: a #GepubWidget
+ *
+ * Change the page to the prev
+ */
+void
+gepub_widget_page_prev (GepubWidget *widget)
+{
+    webkit_web_view_run_javascript(WEBKIT_WEB_VIEW (widget), "prev();", NULL, NULL, NULL);
+}
diff --git a/libgepub/gepub-widget.h b/libgepub/gepub-widget.h
index b77cc6a..5c4ce84 100644
--- a/libgepub/gepub-widget.h
+++ b/libgepub/gepub-widget.h
@@ -46,6 +46,10 @@ GepubDoc         *gepub_widget_get_doc                         (GepubWidget *wid
 void              gepub_widget_set_doc                         (GepubWidget *widget,
                                                                 GepubDoc    *doc);
 
+void              gepub_widget_set_pagination                  (GepubWidget *widget, gboolean p);
+void              gepub_widget_page_next                       (GepubWidget *widget);
+void              gepub_widget_page_prev                       (GepubWidget *widget);
+
 G_END_DECLS
 
 #endif /* __GEPUB_WIDGET_H__ */
diff --git a/tests/test-gepub.c b/tests/test-gepub.c
index 20048d4..4aa5f29 100644
--- a/tests/test-gepub.c
+++ b/tests/test-gepub.c
@@ -69,11 +69,19 @@ void
 button_pressed (GtkButton *button, GepubWidget *widget)
 {
     GepubDoc *doc = gepub_widget_get_doc (widget);
+    printf("CLICKED %s\n",  gtk_button_get_label (button));
 
-    if (!strcmp (gtk_button_get_label (button), "prev")) {
+    if (!strcmp (gtk_button_get_label (button), "< chapter")) {
         gepub_doc_go_prev (doc);
-    } else {
+    } else if (!strcmp (gtk_button_get_label (button), "chapter >")) {
         gepub_doc_go_next (doc);
+    } else if (!strcmp (gtk_button_get_label (button), "< page")) {
+        gepub_widget_page_prev (widget);
+    } else if (!strcmp (gtk_button_get_label (button), "page >")) {
+        gepub_widget_page_next (widget);
+    } else if (!strcmp (gtk_button_get_label (button), "paginated")) {
+        gboolean b = gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (button));
+        gepub_widget_set_pagination (widget, b);
     }
     update_text (doc);
     print_replaced_text (doc);
@@ -245,6 +253,11 @@ main (int argc, char **argv)
     GtkWidget *b_next;
     GtkWidget *b_prev;
 
+    GtkWidget *b_next2;
+    GtkWidget *b_prev2;
+
+    GtkWidget *paginate;
+
     GtkTextBuffer *buffer;
 
     GepubDoc *doc;
@@ -285,12 +298,26 @@ main (int argc, char **argv)
 
     vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
     hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-    b_prev = gtk_button_new_with_label ("prev");
+    b_prev = gtk_button_new_with_label ("< chapter");
     g_signal_connect (b_prev, "clicked", (GCallback)button_pressed, GEPUB_WIDGET (widget));
-    b_next = gtk_button_new_with_label ("next");
+    b_next = gtk_button_new_with_label ("chapter >");
     g_signal_connect (b_next, "clicked", (GCallback)button_pressed, GEPUB_WIDGET (widget));
+
+    b_prev2 = gtk_button_new_with_label ("< page");
+    g_signal_connect (b_prev2, "clicked", (GCallback)button_pressed, GEPUB_WIDGET (widget));
+    b_next2 = gtk_button_new_with_label ("page >");
+    g_signal_connect (b_next2, "clicked", (GCallback)button_pressed, GEPUB_WIDGET (widget));
+
+    paginate = gtk_check_button_new_with_label ("paginated");
+    g_signal_connect (paginate, "clicked", (GCallback)button_pressed, GEPUB_WIDGET (widget));
+
     gtk_container_add (GTK_CONTAINER (hbox), b_prev);
     gtk_container_add (GTK_CONTAINER (hbox), b_next);
+
+    gtk_container_add (GTK_CONTAINER (hbox), b_prev2);
+    gtk_container_add (GTK_CONTAINER (hbox), b_next2);
+    gtk_container_add (GTK_CONTAINER (hbox), paginate);
+
     gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, FALSE, 5);
     gtk_box_pack_start (GTK_BOX (vbox), scrolled, TRUE, TRUE, 5);