GUI2/Widget: added ability to set widget alignment on the fly

src/gui/widgets/grid.cpp

@@ -17,6 +17,7 @@
 #include "gui/widgets/grid_private.hpp"
 
 #include "gui/auxiliary/iterator/walker_grid.hpp"
+#include "gui/core/event/message.hpp"
 #include "gui/core/log.hpp"
 #include "gui/core/layout_exception.hpp"
 #include "gui/widgets/styled_widget.hpp"
@@ -232,7 +233,7 @@ void grid::reduce_width(const unsigned maximum_width)
 
 	/** @todo Implement. */
 
-	/***** ***** ***** ***** Acknowlegde failure ***** ***** ***** *****/
+	/***** ***** ***** ***** Acknowledge failure ***** ***** ***** *****/
 
 	DBG_GUI_L << LOG_HEADER << " Resizing failed.\n";
 
@@ -310,7 +311,7 @@ void grid::reduce_height(const unsigned maximum_height)
 
 	/** @todo Implement. */
 
-	/***** ***** ***** ***** Acknowlegde failure ***** ***** ***** *****/
+	/***** ***** ***** ***** Acknowledge failure ***** ***** ***** *****/
 
 	DBG_GUI_L << LOG_HEADER << " Resizing failed.\n";
 
@@ -946,6 +947,34 @@ grid::child* grid::get_child(widget* w)
 	return nullptr;
 }
 
+void grid::set_child_alignment(widget* widget, unsigned set_flag, unsigned mode_mask)
+{
+	grid::child* cell = get_child(widget);
+	if(!cell) {
+		return;
+	}
+
+	unsigned flags = cell->get_flags();
+
+	if((flags & mode_mask) == HORIZONTAL_GROW_SEND_TO_CLIENT) {
+		ERR_GUI_G << "Cannot set horizontal alignment (grid cell specifies dynamic growth)" << std::endl;
+		return;
+	}
+
+	if((flags & mode_mask) == VERTICAL_GROW_SEND_TO_CLIENT) {
+		ERR_GUI_G << "Cannot set vertical alignment (grid cell specifies dynamic growth)" << std::endl;
+		return;
+	}
+
+	flags &= ~mode_mask;
+	flags |= set_flag;
+
+	cell->set_flags(flags);
+
+	event::message message;
+	fire(event::REQUEST_PLACEMENT, *this, message);
+}
+
 void grid::layout(const point& origin)
 {
 	point orig = origin;

src/gui/widgets/grid.hpp

@@ -227,6 +227,16 @@ public:
 	 */
 	point recalculate_best_size();
 
+	/**
+	 * Modifies the widget alignment data of a child cell containing a specific widget.
+	 *
+	 * @param widget              The widget whose cell to modify.
+	 * @param set_flag            The alignment flag to set.
+	 * @param mask                Whether to affect horizontal or vertical alignment.
+	 *                            Use either HORIZONTAL_MASK or VERTICAL_MASK
+	 */
+	void set_child_alignment(widget* widget, unsigned set_flag, unsigned mode_mask);
+
 private:
 	/** See @ref widget::calculate_best_size. */
 	virtual point calculate_best_size() const override;

src/gui/widgets/widget.cpp

@@ -19,6 +19,7 @@
 #include "gui/widgets/window.hpp"
 #include "gui/core/event/message.hpp"
 #include "gui/core/log.hpp"
+#include "gui/core/window_builder/helper.hpp"
 #include "sdl/rect.hpp"
 
 namespace gui2
@@ -268,6 +269,32 @@ void widget::move(const int x_offset, const int y_offset)
 	y_ += y_offset;
 }
 
+void widget::set_horizontal_alignment(const std::string& alignment)
+{
+	grid* parent_grid = get_parent_grid();
+	if(!parent_grid) {
+		return;
+	}
+
+	parent_grid->set_child_alignment(this, implementation::get_h_align(alignment), grid::HORIZONTAL_MASK);
+
+	// TODO: evaluate necessity
+	//get_window()->invalidate_layout();
+}
+
+void widget::set_vertical_alignment(const std::string& alignment)
+{
+	grid* parent_grid = get_parent_grid();
+	if(!parent_grid) {
+		return;
+	}
+
+	parent_grid->set_child_alignment(this, implementation::get_v_align(alignment), grid::VERTICAL_MASK);
+
+	// TODO: evaluate necessity
+	//get_window()->invalidate_layout();
+}
+
 void widget::layout_children()
 {
 	/* DO NOTHING */

src/gui/widgets/widget.hpp

@@ -181,6 +181,9 @@ public:
 	 */
 	window* get_window();
 
+	/** The constant version of @ref get_window. */
+	const window* get_window() const;
+
 	/**
 	 * Get the parent grid.
 	 *
@@ -189,9 +192,6 @@ public:
 	 */
 	grid* get_parent_grid();
 
-	/** The constant version of @ref get_window. */
-	const window* get_window() const;
-
 	/**
 	 * Returns the top-level dialog.
 	 *
@@ -203,7 +203,7 @@ public:
 	 * function will be removed.
 	 *
 	 * @returns                   The top-level dialog.
-	 * @retval nullptr               No top-level window or the top-level window is
+	 * @retval nullptr            No top-level window or the top-level window is
 	 *                            not owned by a dialog.
 	 */
 	dialogs::modal_dialog* dialog();
@@ -401,6 +401,20 @@ public:
 	 */
 	virtual void move(const int x_offset, const int y_offset);
 
+	/**
+	 * Sets the horizontal alignment of the widget within its parent grid.
+	 *
+	 * @param alignment           The new alignment.
+	 */
+	virtual void set_horizontal_alignment(const std::string& alignment);
+
+	/**
+	 * Sets the horizontal alignment of the widget within its parent grid.
+	 *
+	 * @param alignment           The new alignment.
+	 */
+	virtual void set_vertical_alignment(const std::string& alignment);
+
 	/**
 	 * Allows a widget to update its children.
 	 *