Add cell size preview to dialog

glade/dialog.glade

@@ -4,7 +4,7 @@
   <requires lib="gtk+" version="3.20"/>
   <object class="GtkAdjustment" id="adjustment1">
     <property name="lower">1</property>
-    <property name="upper">3000</property>
+    <property name="upper">4000</property>
     <property name="value">1000</property>
     <property name="step_increment">10</property>
     <property name="page_increment">1000</property>
@@ -69,6 +69,7 @@
         <property name="visible">True</property>
         <property name="can_focus">True</property>
         <property name="adjustment">adjustment1</property>
+        <property name="fill_level">4000</property>
         <property name="round_digits">0</property>
         <property name="digits">0</property>
       </object>
@@ -108,7 +109,7 @@
     </child>
     <child>
       <object class="GtkDrawingArea" id="shape-drawer">
-        <property name="height_request">100</property>
+        <property name="height_request">200</property>
         <property name="visible">True</property>
         <property name="can_focus">False</property>
       </object>
@@ -118,5 +119,38 @@
         <property name="position">6</property>
       </packing>
     </child>
+    <child>
+      <object class="GtkBox">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <child>
+          <object class="GtkLabel" id="x-label">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+          </object>
+          <packing>
+            <property name="expand">True</property>
+            <property name="fill">True</property>
+            <property name="position">0</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkLabel" id="y-label">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+          </object>
+          <packing>
+            <property name="expand">True</property>
+            <property name="fill">True</property>
+            <property name="position">1</property>
+          </packing>
+        </child>
+      </object>
+      <packing>
+        <property name="expand">False</property>
+        <property name="fill">True</property>
+        <property name="position">7</property>
+      </packing>
+    </child>
   </object>
 </interface>

widgets/conv-settings-dialog.c

@@ -39,12 +39,16 @@ struct  _RendererSettingsDialog {
 		GtkWidget *scale;
 		GtkWidget *layer_check;
 		GtkWidget *standalone_check;
+		GtkDrawingArea *shape_drawing;
+		GtkLabel *x_label;
+		GtkLabel *y_label;
+
+		double cell_height;
+		double cell_width;
 };
 
 G_DEFINE_TYPE(RendererSettingsDialog, renderer_settings_dialog, GTK_TYPE_DIALOG)
 
-
-
 static void renderer_settings_dialog_class_init(RendererSettingsDialogClass *klass)
 {
 	/*  No special code needed. Child cells are destroyed automatically due to reference counter */
@@ -72,11 +76,59 @@ static void latex_render_callback(GtkToggleButton *radio, RendererSettingsDialog
 		hide_tex_options(dialog);
 }
 
+static gboolean shape_drawer_drawing_callback(GtkWidget *widget, cairo_t *cr, gpointer data)
+{
+	int width;
+	int height;
+	GtkStyleContext *style_context;
+	GdkRGBA foreground_color;
+	RendererSettingsDialog *dialog = (RendererSettingsDialog *)data;
+	double usable_width;
+	double usable_height;
+	double height_scale;
+	double width_scale;
+	double final_scale_value;
+
+	style_context = gtk_widget_get_style_context(widget);
+	width = gtk_widget_get_allocated_width(widget);
+	height = gtk_widget_get_allocated_height(widget);
+
+	gtk_render_background(style_context, cr, 0, 0, width, height);
+
+	gtk_style_context_get_color(style_context, gtk_style_context_get_state(style_context),
+					&foreground_color);
+
+	gdk_cairo_set_source_rgba(cr, &foreground_color);
+
+	cairo_save(cr);
+
+	/* Tranform coordiante system */
+	cairo_scale(cr, 1, -1);
+	cairo_translate(cr, (double)width/2.0, -(double)height/2.0);
+
+	/* Define usable drawing area */
+	usable_width = (0.95*(double)width) - 15.0;
+	usable_height = (0.95*(double)height) - 15.0;
+
+	width_scale = usable_width/dialog->cell_width;
+	height_scale = usable_height/dialog->cell_height;
+
+	final_scale_value = (width_scale < height_scale ? width_scale : height_scale);
+
+	cairo_rectangle(cr, -dialog->cell_width*final_scale_value/2, -dialog->cell_height*final_scale_value/2,
+				dialog->cell_width*final_scale_value, dialog->cell_height*final_scale_value);
+	cairo_stroke(cr);
+	cairo_restore(cr);
+
+	return FALSE;
+}
+
 static void renderer_settings_dialog_init(RendererSettingsDialog *self)
 {
 	GtkBuilder *builder;
 	GtkWidget *box;
 	GtkDialog *dialog;
+	char default_buff[100];
 
 
 	dialog = &(self->parent);
@@ -89,12 +141,26 @@ static void renderer_settings_dialog_init(RendererSettingsDialog *self)
 	self->scale = GTK_WIDGET(gtk_builder_get_object(builder, "dialog-scale"));
 	self->standalone_check = GTK_WIDGET(gtk_builder_get_object(builder, "standalone-check"));
 	self->layer_check = GTK_WIDGET(gtk_builder_get_object(builder, "layer-check"));
+	self->shape_drawing = GTK_DRAWING_AREA(gtk_builder_get_object(builder, "shape-drawer"));
+	self->x_label = GTK_LABEL(gtk_builder_get_object(builder, "x-label"));
+	self->y_label = GTK_LABEL(gtk_builder_get_object(builder, "y-label"));
 
 	gtk_dialog_add_buttons(dialog, "Cancel", GTK_RESPONSE_CANCEL, "OK", GTK_RESPONSE_OK, NULL);
 	gtk_container_add(GTK_CONTAINER(gtk_dialog_get_content_area(dialog)), box);
 	gtk_window_set_title(GTK_WINDOW(self), "Renderer Settings");
 
 	g_signal_connect(self->radio_latex, "toggled", G_CALLBACK(latex_render_callback), (gpointer)self);
+	g_signal_connect(G_OBJECT(self->shape_drawing),
+				"draw", G_CALLBACK(shape_drawer_drawing_callback), (gpointer)self);
+
+	/* Default values */
+	self->cell_width = 1E-6;
+	self->cell_height = 1E-6;
+
+	snprintf(default_buff, sizeof(default_buff), "Width: %E", self->cell_width);
+	gtk_label_set_text(self->x_label, default_buff);
+	snprintf(default_buff, sizeof(default_buff), "Height: %E", self->cell_height);
+	gtk_label_set_text(self->y_label, default_buff);
 
 	g_object_unref(builder);
 }
@@ -155,9 +221,35 @@ void renderer_settings_dialog_set_settings(RendererSettingsDialog *dialog, struc
 		hide_tex_options(dialog);
 		gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(dialog->radio_cairo_svg), TRUE);
 		break;
-
-
 	}
 }
 
+void renderer_settings_dialog_set_cell_width(RendererSettingsDialog *dialog, double width)
+{
+	if (!dialog)
+		return;
+
+	if (width == 0.0)
+		width = 1E-6;
+
+	if (width < 0.0)
+		width = -width;
+
+	dialog->cell_width = width;
+}
+
+void renderer_settings_dialog_set_cell_height(RendererSettingsDialog *dialog, double height)
+{
+	if (!dialog)
+		return;
+
+	if (height == 0.0)
+		height = 1E-6;
+
+	if (height < 0.0)
+		height = -height;
+
+	dialog->cell_height = height;
+}
+
 /** @} */

widgets/conv-settings-dialog.h

@@ -75,6 +75,20 @@ void renderer_settings_dialog_set_settings(RendererSettingsDialog *dialog, struc
  */
 void renderer_settings_dialog_get_settings(RendererSettingsDialog *dialog, struct render_settings *settings);
 
+/**
+ * @brief renderer_settings_dialog_set_cell_width Set width for rendered cell
+ * @param dialog
+ * @param width Width in meters
+ */
+void renderer_settings_dialog_set_cell_width(RendererSettingsDialog *dialog, double width);
+
+/**
+ * @brief renderer_settings_dialog_set_cell_height Set height for rendered cell
+ * @param dialog
+ * @param height Height in meters
+ */
+void renderer_settings_dialog_set_cell_height(RendererSettingsDialog *dialog, double height);
+
 #endif /* __CONV_SETTINGS_DIALOG_H__ */
 
 /** @} */