Add the preview pane for the campaign dialog.

The pane still needs quite a bit tuning and the extra layout phase looks
rather bad.

data/gui/default/window/campaign_dialog.cfg

@@ -95,10 +95,46 @@
 
 								border = "all"
 								border_size = 5
+								vertical_alignment = "top"
 
 								# FIXME show the addon pane.
-								[spacer]
-								[/spacer]
+								[panel]
+									definition = "default"
+									[grid]
+
+										[row]
+											grow_factor = 0
+
+											[column]
+
+												[scroll_label]
+													id = "description"
+													definition = "default"
+												[/scroll_label]
+
+											[/column]
+
+										[/row]
+
+										[row]
+											grow_factor = 1
+
+											[column]
+												horizontal_alignment = "center"
+												vertical_alignment = "top"
+
+												[image]
+													id = "image"
+													definition = "default"
+												[/image]
+
+											[/column]
+
+										[/row]
+
+									[/grid]
+
+								[/panel]
 
 							[/column]
 

src/gui/dialogs/campaign_selection.cpp

@@ -16,12 +16,40 @@
 
 #include "gui/dialogs/campaign_selection.hpp"
 
+#include "gui/dialogs/helper.hpp"
+#include "gui/widgets/image.hpp"
 #include "gui/widgets/listbox.hpp"
+#include "gui/widgets/scroll_label.hpp"
 #include "gui/widgets/settings.hpp"
 #include "gui/widgets/window.hpp"
 
 namespace gui2 {
 
+void tcampaign_selection::campaign_selected(twindow& window)
+{
+	tlistbox* list = dynamic_cast<tlistbox*>(
+			window.find_widget("campaign_list", false));
+	VALIDATE(list, missing_widget("campaign_list"));
+
+	// Get the selected row
+	config::child_list::const_iterator itor = begin_
+			+ list->get_selected_row(); 
+
+	tscroll_label* scroll_label = dynamic_cast<tscroll_label*>(
+			window.find_widget("description", false));
+	if(scroll_label) {
+		scroll_label->set_label((**itor)["description"]);
+	}
+
+	timage* image = dynamic_cast<timage*>(
+			window.find_widget("image", false));
+	if(image) {
+		image->set_label((**itor)["image"]);
+	}
+
+	window.invalidate_layout();
+}
+
 twindow* tcampaign_selection::build_window(CVideo& video)
 {
 	return build(video, get_id(CAMPAIGN_SELECTION));
@@ -33,6 +61,9 @@ void tcampaign_selection::pre_show(CVideo& /*video*/, twindow& window)
 			window.find_widget("campaign_list", false));
 	VALIDATE(list, missing_widget("campaign_list"));
 
+	list->set_callback_value_change(dialog_callback
+			<tcampaign_selection, &tcampaign_selection::campaign_selected>);
+
 	for(config::child_list::const_iterator itor = begin_;
 			itor != end_; ++itor) {
 
@@ -42,6 +73,7 @@ void tcampaign_selection::pre_show(CVideo& /*video*/, twindow& window)
 		list->add_row(item);
 	}
 
+	campaign_selected(window);
 }
 
 void tcampaign_selection::post_show(twindow& window)

src/gui/dialogs/campaign_selection.hpp

@@ -37,6 +37,9 @@ public:
 
 	int get_choice() const { return choice_; }
 
+	/** Called when another campaign is selected. */
+	void campaign_selected(twindow& window);
+
 private:
 
 	/** Inherited from tdialog. */