Enable displaying of Mapnik configuration extra parameters.

Extend the sample configuration with some such parameters.
gdt · Feb 10, 2015 · 581feee · 581feee
1 parent a8374fc
commit 581feee
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diff --git a/src/mapnik_interface.cpp b/src/mapnik_interface.cpp
@@ -246,6 +246,29 @@ GdkPixbuf* mapnik_interface_render ( MapnikInterface* mi, double lat_tl, double
 	return pixbuf;
 }
 
+/**
+ * 'Parameter' information about the Map configuration
+ *
+ * Free every string element and the returned GArray itself after use
+ */
+GArray* mapnik_interface_get_parameters ( MapnikInterface* mi )
+{
+	GArray *array = g_array_new (FALSE, TRUE, sizeof(gchar*));
+
+	mapnik::parameters pmts = mi->myMap->get_extra_parameters();
+	for (mapnik::parameters::const_iterator ii = pmts.begin(); ii != pmts.end(); ii++) {
+		// Dodgy hacking to avoid using boost or mapnik::utils visitor stuff (not available in mapnik 2.2)
+		// Simply want the strings of each parameter so we can display something...
+		std::stringstream ss;
+		ss << ii->first << ": " << ii->second;
+		// Copy - otherwise ss goes output scope and junk memory would be referenced.
+		gchar *str2 = g_strdup ( (gchar*)ss.str().c_str() );
+		g_array_append_val ( array, str2 );
+	}
+
+	return array;
+}
+
 /**
  * General information about Mapnik
  *

diff --git a/src/mapnik_interface.h b/src/mapnik_interface.h
@@ -26,6 +26,7 @@
 extern "C" {
 #endif
 
+#include <glib.h>
 #include <gdk-pixbuf/gdk-pixbuf.h>
 
 typedef struct _MapnikInterface MapnikInterface;
@@ -42,6 +43,8 @@ gchar* mapnik_interface_load_map_file ( MapnikInterface* mi,
 
 GdkPixbuf* mapnik_interface_render ( MapnikInterface* mi, double lat_tl, double lon_tl, double lat_br, double lon_br );
 
+GArray* mapnik_interface_get_parameters ( MapnikInterface* mi );
+
 gchar * mapnik_interface_about ( void );
 
 #ifdef __cplusplus

diff --git a/src/vikmapniklayer.c b/src/vikmapniklayer.c
@@ -954,6 +954,24 @@ static void mapnik_layer_carto ( menu_array_values values )
 		mapnik_layer_draw ( vml, vvp );
 }
 
+/**
+ * Show Mapnik configuration parameters
+ */
+static void mapnik_layer_information ( menu_array_values values )
+{
+	VikMapnikLayer *vml = values[MA_VML];
+	if ( !vml->mi )
+		return;
+	GArray *array = mapnik_interface_get_parameters( vml->mi );
+	if ( array->len ) {
+		a_dialog_list (  VIK_GTK_WINDOW_FROM_LAYER(vml), _("Mapnik Information"), array, 1 );
+		// Free the copied strings
+		for ( int i = 0; i < array->len; i++ )
+			g_free ( g_array_index(array,gchar*,i) );
+	}
+	g_array_free ( array, FALSE );
+}
+
 /**
  *
  */
@@ -1000,6 +1018,11 @@ static void mapnik_layer_add_menu_items ( VikMapnikLayer *vml, GtkMenu *menu, gp
 		gtk_widget_show ( item );
 	}
 
+	item = gtk_image_menu_item_new_from_stock ( GTK_STOCK_INFO, NULL );
+	g_signal_connect_swapped ( G_OBJECT(item), "activate", G_CALLBACK(mapnik_layer_information), values );
+	gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);
+	gtk_widget_show ( item );
+
 	item = gtk_image_menu_item_new_from_stock ( GTK_STOCK_ABOUT, NULL );
 	g_signal_connect_swapped ( G_OBJECT(item), "activate", G_CALLBACK(mapnik_layer_about), values );
 	gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);

diff --git a/test/Mapnik-ne_110m_admin_0_countries.xml b/test/Mapnik-ne_110m_admin_0_countries.xml
@@ -1,5 +1,11 @@
 <Map background-color="steelblue" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
 
+<Parameters>
+  <Parameter name="name"><![CDATA[Admin Countries]]></Parameter>
+  <Parameter name="description"><![CDATA[Simple country boundaries]]></Parameter>
+  <Parameter name="attribution"><![CDATA[Natural Earth]]></Parameter>
+</Parameters>
+
   <Style name="My Style">
     <Rule>
       <PolygonSymbolizer fill="#f2eff9" />