(svn r16670) -Codechange: Containers with equally sized children are useful to have.

3 files changed, 62 insertions, 26 deletions

diff --git a/src/intro_gui.cpp b/src/intro_gui.cpp
index 6b1ff57f7..db5c56056 100644
--- a/src/intro_gui.cpp
+++ b/src/intro_gui.cpp
@@ -131,7 +131,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 		NWidget(NWID_SPACER), SetMinimalSize(0, 8),
 
 		/* 'generate game' and 'load game' buttons */
-		NWidget(NWID_HORIZONTAL),
+		NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 			NWidget(NWID_SPACER), SetMinimalSize(10, 0),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_GENERATE_GAME), SetMinimalSize(158, 12),
 								SetDataTip(STR_INTRO_NEW_GAME, STR_INTRO_TOOLTIP_NEW_GAME),
@@ -143,7 +143,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 		NWidget(NWID_SPACER), SetMinimalSize(0, 6),
 
 		/* 'play scenario' and 'play heightmap' buttons */
-		NWidget(NWID_HORIZONTAL),
+		NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 			NWidget(NWID_SPACER), SetMinimalSize(10, 0),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_PLAY_SCENARIO), SetMinimalSize(158, 12),
 								SetDataTip(STR_INTRO_PLAY_SCENARIO, STR_INTRO_TOOLTIP_PLAY_SCENARIO),
@@ -155,7 +155,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 		NWidget(NWID_SPACER), SetMinimalSize(0, 6),
 
 		/* 'edit scenario' and 'play multiplayer' buttons */
-		NWidget(NWID_HORIZONTAL),
+		NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 			NWidget(NWID_SPACER), SetMinimalSize(10, 0),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_EDIT_SCENARIO), SetMinimalSize(158, 12),
 								SetDataTip(STR_INTRO_SCENARIO_EDITOR, STR_INTRO_TOOLTIP_SCENARIO_EDITOR),
@@ -185,7 +185,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 		NWidget(NWID_SPACER), SetMinimalSize(0, 7),
 
 		/* 'game options' and 'difficulty options' buttons */
-		NWidget(NWID_HORIZONTAL),
+		NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 			NWidget(NWID_SPACER), SetMinimalSize(10, 0),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_OPTIONS), SetMinimalSize(158, 12),
 								SetDataTip(STR_INTRO_GAME_OPTIONS, STR_INTRO_TOOLTIP_GAME_OPTIONS),
@@ -197,7 +197,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 		NWidget(NWID_SPACER), SetMinimalSize(0, 6),
 
 		/* 'advanced settings' and 'newgrf settings' buttons */
-		NWidget(NWID_HORIZONTAL),
+		NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 			NWidget(NWID_SPACER), SetMinimalSize(10, 0),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_SETTINGS_OPTIONS), SetMinimalSize(158, 12),
 								SetDataTip(STR_CONFIG_SETTING, STR_CONFIG_SETTING_TIP),
@@ -209,7 +209,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 		NWidget(NWID_SPACER), SetMinimalSize(0, 6),
 
 		/* 'online content' and 'ai settings' buttons */
-		NWidget(NWID_HORIZONTAL),
+		NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 			NWidget(NWID_SPACER), SetMinimalSize(10, 0),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_CONTENT_DOWNLOAD), SetMinimalSize(158, 12),
 								SetDataTip(STR_CONTENT_INTRO_BUTTON, STR_CONTENT_INTRO_BUTTON_TIP),
diff --git a/src/widget.cpp b/src/widget.cpp
index f937c401f..dc8a3598e 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -1340,8 +1340,9 @@ NWidgetCore *NWidgetStacked::GetWidgetFromPos(int x, int y)
 	return NULL;
 }
 
-NWidgetPIPContainer::NWidgetPIPContainer(WidgetType tp) : NWidgetContainer(tp)
+NWidgetPIPContainer::NWidgetPIPContainer(WidgetType tp, NWidContainerFlags flags) : NWidgetContainer(tp)
 {
+	this->flags = flags;
 }
 
 /**
@@ -1379,7 +1380,7 @@ NWidgetCore *NWidgetPIPContainer::GetWidgetFromPos(int x, int y)
 }
 
 /** Horizontal container widget. */
-NWidgetHorizontal::NWidgetHorizontal() : NWidgetPIPContainer(NWID_HORIZONTAL)
+NWidgetHorizontal::NWidgetHorizontal(NWidContainerFlags flags) : NWidgetPIPContainer(NWID_HORIZONTAL, flags)
 {
 }
 
@@ -1393,11 +1394,22 @@ int NWidgetHorizontal::SetupSmallestSize()
 	this->resize_x = 0;     // smallest non-zero child widget resize step.
 	this->resize_y = 1;     // smallest common child resize step
 
-	if (this->head != NULL) this->head->padding_left += this->pip_pre;
+	/* 1. Forward call, collect biggest nested array index, and longest child length. */
+	uint longest = 0; // Longest child found.
 	for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
 		int idx = child_wid->SetupSmallestSize();
 		biggest_index = max(biggest_index, idx);
-
+		longest = max(longest, child_wid->smallest_x);
+	}
+	/* 2. For containers that must maintain equal width, extend child minimal size. */
+	if (this->flags & NC_EQUALSIZE) {
+		for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
+			if (child_wid->fill_x) child_wid->smallest_x = longest;
+		}
+	}
+	/* 3. Move PIP space to the childs, compute smallest, fill, and resize values of the container. */
+	if (this->head != NULL) this->head->padding_left += this->pip_pre;
+	for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
 		if (child_wid->next != NULL) {
 			child_wid->padding_right += this->pip_inter;
 		} else {
@@ -1503,7 +1515,7 @@ void NWidgetHorizontal::StoreWidgets(Widget *widgets, int length, bool left_movi
 }
 
 /** Horizontal left-to-right container widget. */
-NWidgetHorizontalLTR::NWidgetHorizontalLTR() : NWidgetHorizontal()
+NWidgetHorizontalLTR::NWidgetHorizontalLTR(NWidContainerFlags flags) : NWidgetHorizontal(flags)
 {
 	this->type = NWID_HORIZONTAL_LTR;
 }
@@ -1519,7 +1531,7 @@ void NWidgetHorizontalLTR::StoreWidgets(Widget *widgets, int length, bool left_m
 }
 
 /** Vertical container widget. */
-NWidgetVertical::NWidgetVertical() : NWidgetPIPContainer(NWID_VERTICAL)
+NWidgetVertical::NWidgetVertical(NWidContainerFlags flags) : NWidgetPIPContainer(NWID_VERTICAL, flags)
 {
 }
 
@@ -1533,11 +1545,22 @@ int NWidgetVertical::SetupSmallestSize()
 	this->resize_x = 1;     // smallest common child resize step
 	this->resize_y = 0;     // smallest non-zero child widget resize step.
 
-	if (this->head != NULL) this->head->padding_top += this->pip_pre;
+	/* 1. Forward call, collect biggest nested array index, and longest child length. */
+	uint highest = 0; // Highest child found.
 	for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
 		int idx = child_wid->SetupSmallestSize();
 		biggest_index = max(biggest_index, idx);
-
+		highest = max(highest, child_wid->smallest_y);
+	}
+	/* 2. For containers that must maintain equal width, extend child minimal size. */
+	if (this->flags & NC_EQUALSIZE) {
+		for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
+			if (child_wid->fill_y) child_wid->smallest_y = highest;
+		}
+	}
+	/* 3. Move PIP space to the childs, compute smallest, fill, and resize values of the container. */
+	if (this->head != NULL) this->head->padding_top += this->pip_pre;
+	for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
 		if (child_wid->next != NULL) {
 			child_wid->padding_bottom += this->pip_inter;
 		} else {
@@ -2173,13 +2196,13 @@ static int MakeNWidget(const NWidgetPart *parts, int count, NWidgetBase **dest,
 
 			case NWID_HORIZONTAL:
 				if (*dest != NULL) return num_used;
-				*dest = new NWidgetHorizontal();
+				*dest = new NWidgetHorizontal(parts->u.cont_flags);
 				*fill_dest = true;
 				break;
 
 			case NWID_HORIZONTAL_LTR:
 				if (*dest != NULL) return num_used;
-				*dest = new NWidgetHorizontalLTR();
+				*dest = new NWidgetHorizontalLTR(parts->u.cont_flags);
 				*fill_dest = true;
 				break;
 
@@ -2193,7 +2216,7 @@ static int MakeNWidget(const NWidgetPart *parts, int count, NWidgetBase **dest,
 
 			case NWID_VERTICAL:
 				if (*dest != NULL) return num_used;
-				*dest = new NWidgetVertical();
+				*dest = new NWidgetVertical(parts->u.cont_flags);
 				*fill_dest = true;
 				break;
 
diff --git a/src/widget_type.h b/src/widget_type.h
index b62e82d97..084f36be8 100644
--- a/src/widget_type.h
+++ b/src/widget_type.h
@@ -363,10 +363,19 @@ public:
 	/* virtual */ NWidgetCore *GetWidgetFromPos(int x, int y);
 };
 
+/** Nested widget container flags, */
+enum NWidContainerFlags {
+	NCB_EQUALSIZE = 0, ///< Containers should keep all their (resizing) children equally large.
+
+	NC_NONE = 0,                       ///< All flags cleared.
+	NC_EQUALSIZE = 1 << NCB_EQUALSIZE, ///< Value of the #NCB_EQUALSIZE flag.
+};
+DECLARE_ENUM_AS_BIT_SET(NWidContainerFlags);
+
 /** Container with pre/inter/post child space. */
 class NWidgetPIPContainer : public NWidgetContainer {
 public:
-	NWidgetPIPContainer(WidgetType tp);
+	NWidgetPIPContainer(WidgetType tp, NWidContainerFlags flags = NC_NONE);
 
 	void SetPIP(uint8 pip_pre, uint8 pip_inter, uint8 pip_post);
 
@@ -374,16 +383,17 @@ public:
 	/* virtual */ NWidgetCore *GetWidgetFromPos(int x, int y);
 
 protected:
-	uint8 pip_pre;     ///< Amount of space before first widget.
-	uint8 pip_inter;   ///< Amount of space between widgets.
-	uint8 pip_post;    ///< Amount of space after last widget.
+	NWidContainerFlags flags; ///< Flags of the container.
+	uint8 pip_pre;            ///< Amount of space before first widget.
+	uint8 pip_inter;          ///< Amount of space between widgets.
+	uint8 pip_post;           ///< Amount of space after last widget.
 };
 
 /** Horizontal container.
  * @ingroup NestedWidgets */
 class NWidgetHorizontal : public NWidgetPIPContainer {
 public:
-	NWidgetHorizontal();
+	NWidgetHorizontal(NWidContainerFlags flags = NC_NONE);
 
 	int SetupSmallestSize();
 	void AssignSizePosition(SizingType sizing, uint x, uint y, uint given_width, uint given_height, bool allow_resize_x, bool allow_resize_y, bool rtl);
@@ -395,7 +405,7 @@ public:
  * @ingroup NestedWidgets */
 class NWidgetHorizontalLTR : public NWidgetHorizontal {
 public:
-	NWidgetHorizontalLTR();
+	NWidgetHorizontalLTR(NWidContainerFlags flags = NC_NONE);
 
 	void AssignSizePosition(SizingType sizing, uint x, uint y, uint given_width, uint given_height, bool allow_resize_x, bool allow_resize_y, bool rtl);
 
@@ -406,7 +416,7 @@ public:
  * @ingroup NestedWidgets */
 class NWidgetVertical : public NWidgetPIPContainer {
 public:
-	NWidgetVertical();
+	NWidgetVertical(NWidContainerFlags flags = NC_NONE);
 
 	int SetupSmallestSize();
 	void AssignSizePosition(SizingType sizing, uint x, uint y, uint given_width, uint given_height, bool allow_resize_x, bool allow_resize_y, bool rtl);
@@ -561,6 +571,7 @@ struct NWidgetPart {
 		NWidgetPartPaddings padding;     ///< Part with paddings.
 		NWidgetPartPIP pip;              ///< Part with pre/inter/post spaces.
 		NWidgetFunctionType *func_ptr;   ///< Part with a function call.
+		NWidContainerFlags cont_flags;   ///< Part with container flags.
 	} u;
 };
 
@@ -763,14 +774,16 @@ static inline NWidgetPart NWidget(WidgetType tp, Colours col, int16 idx)
 
 /**
  * Widget part function for starting a new horizontal container, vertical container, or spacer widget.
- * @param tp Type of the new nested widget, #NWID_HORIZONTAL(_LTR), #NWID_VERTICAL, #NWID_SPACER, #NWID_SELECTION, or #NWID_LAYERED.
+ * @param tp         Type of the new nested widget, #NWID_HORIZONTAL(_LTR), #NWID_VERTICAL, #NWID_SPACER, #NWID_SELECTION, or #NWID_LAYERED.
+ * @param cont_flags Flags for the containers (#NWID_HORIZONTAL(_LTR) and #NWID_VERTICAL).
  * @ingroup NestedWidgetParts
  */
-static inline NWidgetPart NWidget(WidgetType tp)
+static inline NWidgetPart NWidget(WidgetType tp, NWidContainerFlags cont_flags = NC_NONE)
 {
 	NWidgetPart part;
 
 	part.type = tp;
+	part.u.cont_flags = cont_flags;
 
 	return part;
 }