Make wrapping for dialogs work nicely.

As long as the text is shown without a scrollbar the window closes on a
mouse click. When the scrollbar is needed a button will also be shown
and a mouse click (expect on the button) won't close the window anymore.

data/gui/default/window/message.cfg

@@ -575,9 +575,7 @@
 				[/column]
 
 			[/row]
-# Comment out the button for now since it's no longer needed.
-# It will be reenabled later to show the buttons optionally.
-#ifdef GUI_NO_SUCH_DEFINITION
+
 			[row]
 
 				[column]
@@ -586,6 +584,9 @@
 					horizontal_alignment = "center"
 
 					[button]
+						# This button will be shown or hidden depending on the
+						# whether or not a scrollbar is needed to show the
+						# text.
 						id = "ok"
 						definition = "default"
 
@@ -595,7 +596,7 @@
 				[/column]
 
 			[/row]
-#endif
+
 		[/grid]
 
 	[/resolution]

src/gui/dialogs/message.cpp

@@ -44,13 +44,38 @@ void tmessage::pre_show(CVideo& /*video*/, twindow& window)
 	VALIDATE(label, missing_widget("label"));
 
 	label->set_label(message_);
+
+	if(auto_close_) {
+		/*
+		 * Hide the buttton and do the layout, if window.does_easy_close() is
+		 * false the scroll_label has a scrollbar so we need to show the
+		 * button. When the button is hidden the text for the label is bigger
+		 * and thus not need a scrollbar. Also when the button is visible
+		 * easy_close will always return false.
+		 */
+		/** @todo The space for invisible items is always reserved. Look about
+		 * how to change that. (Maybe get_best_size() in twidget can do that by
+		 * returning 0,0 when called upon invisible items. Or the tgrid::tchild
+		 * should do that since an item with 0,0 might get a border.)
+		 */
+		tcontrol* button = 
+			dynamic_cast<tcontrol*>(window.find_widget("ok", false));
+		button->set_visible(false);
+
+		window.layout();
+
+		if(! window.does_easy_close()) {
+			button->set_visible();
+		}
+	}
 }
 
 /** @todo the caption is ignored. */
 void show_message(CVideo& video, const std::string& title, 
-	const std::string& message, const std::string& /*button_caption*/)
+	const std::string& message, const std::string& /*button_caption*/,
+	const bool auto_close)
 {
-	tmessage(title, message).show(video);
+	tmessage(title, message, auto_close).show(video);
 }
 
 } // namespace gui2

src/gui/dialogs/message.hpp

@@ -28,10 +28,12 @@ namespace gui2 {
 class tmessage : public tdialog
 {
 public:
-	tmessage(const std::string& title, const std::string& message)
+	tmessage(const std::string& title, const std::string& message,
+			const bool auto_close)
 		: title_(title)
 		, image_()
 		, message_(message)
+		, auto_close_(auto_close)
 	{}
 
 	/***** ***** ***** setters / getters for members ***** ****** *****/
@@ -56,6 +58,12 @@ private:
 	/** The message to show to the user. */
 	std::string message_;
 
+	/** 
+	 * Does the window need to use easy_close when the dialog doesn't need a
+	 * scrollbar.
+	 */
+	bool auto_close_;
+
 	/** Inherited from tdialog. */
 	twindow build_window(CVideo& video);
 
@@ -76,9 +84,13 @@ private:
  * @param title               The title of the dialog.
  * @param message             The message to show in the dialog.
  * @param button_caption      The caption of the close button.
+ * @param auto_close          When true the window will hide the ok button
+ *                            when the message doesn't need a scrollbar to
+ *                            show itself.
  */
 void show_message(CVideo& video, const std::string& title, 
-	const std::string& message, const std::string& button_caption = "");
+	const std::string& message, const std::string& button_caption = "",
+	const bool auto_close = true);
 
 } // namespace gui2
 

src/gui/widgets/window.hpp

@@ -47,6 +47,9 @@ class tdebug_layout_graph;
 class twindow : public tpanel, public tevent_handler
 {
 	friend class tdebug_layout_graph;
+
+	// Wants to use layout().
+	friend class tmessage;
 public:
 	twindow(CVideo& video,
 		tformula<unsigned>x,