Adds helper code to assist in widget placement.

The code is used to experiment with a different approach of the
implementation of a listbox.

changelog

@@ -166,6 +166,7 @@ Version 1.11.0-svn:
    * Stop showing a unit's potential moves before moving in a move & attack,
      rather than after (more consistent with regular movement)
    * Changed: Made the id for a tooltip and helptip mandatory.
+   * Added: Helper code to assist in widget placement.
  * Whiteboard:
    * Fixed bug #19626: segfaults on window resize
    * Fixed bug #19369: Using planning mode can cause losing ability to move my units

po/wesnoth-lib/POTFILES.in

@@ -12,6 +12,9 @@ src/gui/auxiliary/iterator/iterator.cpp
 src/gui/auxiliary/iterator/walker_grid.cpp
 src/gui/auxiliary/iterator/walker_widget.cpp
 src/gui/auxiliary/log.cpp
+src/gui/auxiliary/placer.cpp
+src/gui/auxiliary/placer/horizontal_list.cpp
+src/gui/auxiliary/placer/vertical_list.cpp
 src/gui/auxiliary/tips.cpp
 src/gui/auxiliary/widget_definition/button.cpp
 src/gui/auxiliary/widget_definition.cpp

src/CMakeLists.txt

@@ -418,6 +418,9 @@ set(wesnoth-main_SRC
 	gui/auxiliary/iterator/walker_grid.cpp
 	gui/auxiliary/iterator/walker_widget.cpp
 	gui/auxiliary/log.cpp
+	gui/auxiliary/placer.cpp
+	gui/auxiliary/placer/horizontal_list.cpp
+	gui/auxiliary/placer/vertical_list.cpp
 	gui/auxiliary/old_markup.cpp
 	gui/auxiliary/timer.cpp
 	gui/auxiliary/tips.cpp

src/SConscript

@@ -262,6 +262,9 @@ wesnoth_sources = Split("""
     gui/auxiliary/iterator/walker_grid.cpp
     gui/auxiliary/iterator/walker_widget.cpp
     gui/auxiliary/log.cpp
+    gui/auxiliary/placer.cpp
+    gui/auxiliary/placer/horizontal_list.cpp
+    gui/auxiliary/placer/vertical_list.cpp
     gui/auxiliary/old_markup.cpp
     gui/auxiliary/timer.cpp
     gui/auxiliary/tips.cpp

src/gui/auxiliary/placer.cpp

@@ -0,0 +1,49 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-lib"
+
+#define ENUM_ENABLE_STREAM_OPERATORS_IMPLEMENTATION
+#define ENUM_TYPE ::gui2::tplacer_
+#define ENUM_LIST                                                             \
+ENUM(horizontal,                  "horizontal");                              \
+ENUM(vertical,                    "vertical");                                \
+
+#include "gui/auxiliary/placer.hpp"
+
+#include "gui/auxiliary/placer/horizontal_list.hpp"
+#include "gui/auxiliary/placer/vertical_list.hpp"
+
+ENUM_DEFINE_STREAM_OPERATORS(::gui2::tplacer_::tgrow_direction)
+
+namespace gui2 {
+
+tplacer_* tplacer_::build(
+		  const tgrow_direction grow_direction
+		, const unsigned parallel_items)
+{
+	switch(grow_direction) {
+		case horizontal :
+			return new implementation::tplacer_horizontal_list(parallel_items);
+		case vertical :
+			return new implementation::tplacer_vertical_list(parallel_items);
+	};
+}
+
+tplacer_::~tplacer_()
+{
+}
+
+} // namespace gui2

src/gui/auxiliary/placer.hpp

@@ -0,0 +1,130 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+/**
+ * @file
+ * Base class for the placement helper.
+ *
+ * Some items can create new child items and these items are placed in some way
+ * this code contains helpers for the placement by calculating the positions
+ * for the items and the best size for the children.
+ */
+
+#ifndef GUI_AUXILIARY_PLACER_HPP_INCLUDED
+#define GUI_AUXILIARY_PLACER_HPP_INCLUDED
+
+namespace gui2 {
+
+class tpoint;
+
+/**
+ * Base class for the placement helper.
+ *
+ * The normal operation for the usage of the class is:
+ * * Call @ref initialise().
+ * * For every visible child item call @ref add_item() with the wanted size of
+ *   the widget.
+ * Once this is done the required size for all children can be retrieved with
+ * @ref get_size(). It is also possible to place all children now. In order to
+ * do so loop again over all children in the same order as @ref add_item() and
+ * call @ref get_origin(). The @p index parameter is an increasing counter.
+ *
+ * @note The origins can only be retrieved after all items are added since the
+ * adding of a later item may influence a previous item. E.g. in a vertical
+ * list with two columns the position of the second column depends on the width
+ * of the first and a later row may have a wider column 1 as an earlier row.
+ */
+class tplacer_
+{
+public:
+
+	/***** ***** Types. ***** *****/
+
+	/** The direction the placer should grow towards. */
+	enum tgrow_direction
+	{
+		  horizontal
+		, vertical
+	};
+
+
+	/***** ***** Constructor, destructor, assignment. ***** *****/
+
+public:
+
+	/**
+	 * Builder function.
+	 *
+	 * @pre                       @p parallel_items > 0
+	 *
+	 * @param grow_direction      The direction in which the items will be
+	 *                            added.
+	 * @param parallel_items      The direction perpendicular towards the grow
+	 *                            direction has a fixed number of items. This
+	 *                            value sets that limit. For a list containing
+	 *                            only horizontally or vertically placed items
+	 *                            the value should be 1.
+	 */
+	static tplacer_* build(
+			  const tgrow_direction grow_direction
+			, const unsigned parallel_items);
+
+	virtual ~tplacer_();
+
+
+	/***** ***** Operations. ***** *****/
+
+	/**
+	 * Initialises the placer.
+	 *
+	 * When the placement needs to be calculated the state often needs to be
+	 * reset, items are placed, removed or changed visibility causing the old
+	 * placement to be invalid.
+	 */
+	virtual void initialise() = 0;
+
+	/**
+	 * Adds a item to be placed.
+	 *
+	 * @param size                The required size for the item.
+	 */
+	virtual void add_item(const tpoint& size) = 0;
+
+	/**
+	 * Gets the required size of all items.
+	 *
+	 * @returns                   The required size.
+	 */
+	virtual tpoint get_size() const = 0;
+
+	/**
+	 * Gets the origin for an item.
+	 *
+	 * @param index               The index of the item whose origin to return.
+	 *                            The index is the index of the call to
+	 *                            @ref add_item().
+	 *
+	 * @returns                   The origin where to place the widget.
+	 */
+	virtual tpoint get_origin(const unsigned index) const = 0;
+};
+
+} // namespace gui2
+
+#include "enumerate.tpp"
+
+ENUM_DECLARE_STREAM_OPERATORS(::gui2::tplacer_::tgrow_direction)
+
+#endif

src/gui/auxiliary/placer/horizontal_list.cpp

@@ -0,0 +1,89 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-lib"
+
+#include "gui/auxiliary/placer/horizontal_list.hpp"
+
+#include "gui/widgets/helper.hpp"
+
+#include <cassert>
+#include <numeric>
+
+namespace gui2 {
+
+namespace implementation {
+
+tplacer_horizontal_list::tplacer_horizontal_list(const unsigned maximum_rows)
+	: maximum_rows_(maximum_rows)
+	, rows_(maximum_rows, 0)
+	, columns_(1, std::make_pair(0, 0))
+	, row_(0)
+	, column_(0)
+{
+	assert(maximum_rows_ > 0);
+}
+
+void tplacer_horizontal_list::initialise()
+{
+	std::fill(rows_.begin(), rows_.end(), 0);
+	columns_.clear();
+	columns_.push_back(std::make_pair(0, 0));
+	row_ = 0;
+	column_ = 0;
+}
+
+void tplacer_horizontal_list::add_item(const tpoint& size)
+{
+	if(size.x > columns_[column_].second) {
+		columns_[column_].second = size.x;
+	}
+
+	if(size.y > rows_[row_]) {
+		rows_[row_]= size.y;
+	}
+
+	++row_;
+	if(row_ == maximum_rows_) {
+		row_ = 0;
+		++column_;
+
+		const int origin = columns_.back().first + columns_.back().second;
+		columns_.push_back(std::make_pair(origin, 0));
+	}
+}
+
+tpoint tplacer_horizontal_list::get_size() const
+{
+	const int width =  columns_.back().first + columns_.back().second;
+	const int height = std::accumulate(rows_.begin(), rows_.end(), 0);
+	return tpoint(width, height);
+}
+
+tpoint tplacer_horizontal_list::get_origin(const unsigned index) const
+{
+	const unsigned row = index % maximum_rows_;
+	const unsigned column = index / maximum_rows_;
+
+	const int height = row == 0
+			? 0
+			: std::accumulate(rows_.begin(), rows_.begin() + row, 0);
+
+	return tpoint(columns_[column].first, height);
+}
+
+} // namespace implementation
+
+} // namespace gui2

src/gui/auxiliary/placer/horizontal_list.hpp

@@ -0,0 +1,95 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+/**
+ * @file
+ * Placement helper for the horizontal list.
+ */
+
+#ifndef GUI_AUXILIARY_PLACER_HORIZONTAL_LIST_HPP_INCLUDED
+#define GUI_AUXILIARY_PLACER_HORIZONTAL_LIST_HPP_INCLUDED
+
+#include "gui/auxiliary/placer.hpp"
+
+#include <vector>
+
+namespace gui2 {
+
+namespace implementation {
+
+/**
+ * The placement class for a horizontal list.
+ *
+ * @see @ref tplacer_ for more information.
+ */
+class tplacer_horizontal_list
+	: public tplacer_
+{
+
+public:
+
+	/***** ***** Constructor, destructor, assignment. ***** *****/
+
+	explicit tplacer_horizontal_list(const unsigned maximum_rows);
+
+
+	/***** ***** Inherited operations. ***** *****/
+
+	virtual void initialise();
+
+	virtual void add_item(const tpoint& size);
+
+	virtual tpoint get_size() const;
+
+	virtual tpoint get_origin(const unsigned index) const;
+
+
+	/***** ***** Members. ***** *****/
+
+private:
+
+	/**
+	 * The maximum number of rows to use.
+	 *
+	 * This value is determined by the @p parallel_items parameter of
+	 * @ref tplacer_::build).
+	 */
+	unsigned maximum_rows_;
+
+	/** Holds the heights of the rows. */
+	std::vector<int> rows_;
+
+	/**
+	 * Holds the column sizes
+	 *
+	 * The pair contains the following values:
+	 * * first                    The origin of a column.
+	 * * second                   The width of a column.
+	 */
+	std::vector<std::pair<int, int> > columns_;
+
+	/** The row to add an item to. */
+	unsigned row_;
+
+	/** The column to add an item to. */
+	unsigned column_;
+
+};
+
+} // namespace implementation
+
+} // namespace gui2
+
+#endif

src/gui/auxiliary/placer/vertical_list.cpp

@@ -0,0 +1,89 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-lib"
+
+#include "gui/auxiliary/placer/vertical_list.hpp"
+
+#include "gui/widgets/helper.hpp"
+
+#include <cassert>
+#include <numeric>
+
+namespace gui2 {
+
+namespace implementation {
+
+tplacer_vertical_list::tplacer_vertical_list(const unsigned maximum_columns)
+	: maximum_columns_(maximum_columns)
+	, rows_(1, std::make_pair(0, 0))
+	, columns_(maximum_columns, 0)
+	, row_(0)
+	, column_(0)
+{
+	assert(maximum_columns_ > 0);
+}
+
+void tplacer_vertical_list::initialise()
+{
+	rows_.clear();
+	rows_.push_back(std::make_pair(0, 0));
+	std::fill(columns_.begin(), columns_.end(), 0);
+	row_ = 0;
+	column_ = 0;
+}
+
+void tplacer_vertical_list::add_item(const tpoint& size)
+{
+	if(size.x > columns_[column_]) {
+		columns_[column_] = size.x;
+	}
+
+	if(size.y > rows_[row_].second) {
+		rows_[row_].second = size.y;
+	}
+
+	++column_;
+	if(column_ == maximum_columns_) {
+		column_ = 0;
+		++row_;
+
+		const int origin = rows_.back().first + rows_.back().second;
+		rows_.push_back(std::make_pair(origin, 0));
+	}
+}
+
+tpoint tplacer_vertical_list::get_size() const
+{
+	const int width = std::accumulate(columns_.begin(), columns_.end(), 0);
+	const int height = rows_.back().first + rows_.back().second;
+	return tpoint(width, height);
+}
+
+tpoint tplacer_vertical_list::get_origin(const unsigned index) const
+{
+	const unsigned row = index / maximum_columns_;
+	const unsigned column = index % maximum_columns_;
+
+	const int width = column == 0
+			? 0
+			: std::accumulate(columns_.begin(), columns_.begin() + column, 0);
+
+	return tpoint(width, rows_[row].first);
+}
+
+} // namespace implementation
+
+} // namespace gui2

src/gui/auxiliary/placer/vertical_list.hpp

@@ -0,0 +1,93 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+/**
+ * @file
+ * Placement helper for the vertical list.
+ */
+
+#ifndef GUI_AUXILIARY_PLACER_VERTICAL_LIST_HPP_INCLUDED
+#define GUI_AUXILIARY_PLACER_VERTICAL_LIST_HPP_INCLUDED
+
+#include "gui/auxiliary/placer.hpp"
+
+#include <vector>
+
+namespace gui2 {
+
+namespace implementation {
+
+/**
+ * The placement class for a vertical list.
+ *
+ * @see @ref tplacer_ for more information.
+ */
+class tplacer_vertical_list
+	: public tplacer_
+{
+public:
+
+	/***** ***** Constructor, destructor, assignment. ***** *****/
+
+	explicit tplacer_vertical_list(const unsigned maximum_columns);
+
+
+	/***** ***** Inherited operations. ***** *****/
+
+	virtual void initialise();
+
+	virtual void add_item(const tpoint& size);
+
+	virtual tpoint get_size() const;
+
+	virtual tpoint get_origin(const unsigned index) const;
+
+
+	/***** ***** Members. ***** *****/
+
+private:
+
+	/**
+	 * The maximum number of colums to use.
+	 *
+	 * This value is determined by the @p parallel_items parameter of
+	 * @ref tplacer_::build).
+	 */
+	unsigned maximum_columns_;
+
+	/**
+	 * Holds the row sizes
+	 *
+	 * The pair contains the following values:
+	 * * first                    The origin of a row.
+	 * * second                   The height of a row.
+	 */
+	std::vector<std::pair<int, int> > rows_;
+
+	/** Holds the widths of the columns. */
+	std::vector<int> columns_;
+
+	/** The row to add an item to. */
+	unsigned row_;
+
+	/** The column to add an item to. */
+	unsigned column_;
+};
+
+} // namespace implementation
+
+} // namespace gui2
+
+#endif