(svn r16689) -Codechange: Allow for rendering of parameterized text of nested widgets in Window::DrawWidget, adapt intro and town directory windows.

4 files changed, 103 insertions, 58 deletions

diff --git a/src/intro_gui.cpp b/src/intro_gui.cpp
index 662442ad8..35de114e3 100644
--- a/src/intro_gui.cpp
+++ b/src/intro_gui.cpp
@@ -72,10 +72,17 @@ struct SelectGameWindow : public Window {
 
 	virtual void OnPaint()
 	{
-		SetDParam(0, STR_DIFFICULTY_LEVEL_EASY + _settings_newgame.difficulty.diff_level);
 		this->DrawWidgets();
 	}
 
+	virtual void DrawWidget(const Rect &r, int widget) const
+	{
+		if (widget == SGI_DIFFICULTIES) {
+			SetDParam(0, STR_DIFFICULTY_LEVEL_EASY + _settings_newgame.difficulty.diff_level);
+			DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, r.top + WD_FRAMERECT_TOP, STR_INTRO_DIFFICULTY, TC_FROMSTRING, SA_CENTER);
+		}
+	}
+
 	virtual void OnClick(Point pt, int widget)
 	{
 #ifdef ENABLE_NETWORK
@@ -189,7 +196,7 @@ static const NWidgetPart _nested_select_game_widgets[] = {
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_OPTIONS), SetMinimalSize(158, 12),
 								SetDataTip(STR_INTRO_GAME_OPTIONS, STR_INTRO_TOOLTIP_GAME_OPTIONS), SetPadding(0, 0, 0, 10),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_ORANGE, SGI_DIFFICULTIES), SetMinimalSize(158, 12),
-								SetDataTip(STR_INTRO_DIFFICULTY, STR_INTRO_TOOLTIP_DIFFICULTY_OPTIONS), SetPadding(0, 10, 0, 0),
+								SetDataTip(STR_NULL, STR_INTRO_TOOLTIP_DIFFICULTY_OPTIONS), SetPadding(0, 10, 0, 0),
 		EndContainer(),
 
 		NWidget(NWID_SPACER), SetMinimalSize(0, 6),
diff --git a/src/town_gui.cpp b/src/town_gui.cpp
index 9731d35cd..84ca240c7 100644
--- a/src/town_gui.cpp
+++ b/src/town_gui.cpp
@@ -613,29 +613,40 @@ public:
 		SetVScrollCount(this, this->towns.Length());
 
 		this->DrawWidgets();
-		this->DrawSortButtonState(this->towns.SortType() == 0 ? TDW_SORTNAME : TDW_SORTPOPULATION, this->towns.IsDescSortOrder() ? SBS_DOWN : SBS_UP);
+	}
 
-		{
-			int n = 0;
-			uint16 i = this->vscroll.pos;
-			int y = this->nested_array[TDW_CENTERTOWN]->pos_y + 2;
+	virtual void DrawWidget(const Rect &r, int widget) const
+	{
+		switch(widget) {
+			case TDW_SORTNAME:
+				if (this->towns.SortType() == 0) this->DrawSortButtonState(widget, this->towns.IsDescSortOrder() ? SBS_DOWN : SBS_UP);
+				break;
 
-			while (i < this->towns.Length()) {
-				const Town *t = this->towns[i];
+			case TDW_SORTPOPULATION:
+				if (this->towns.SortType() != 0) this->DrawSortButtonState(widget, this->towns.IsDescSortOrder() ? SBS_DOWN : SBS_UP);
+				break;
 
-				assert(t->xy != INVALID_TILE);
+			case TDW_CENTERTOWN: {
+				int n = 0;
+				int y = r.top + 2;
+				for (uint i = this->vscroll.pos; i < this->towns.Length(); i++) {
+					const Town *t = this->towns[i];
 
-				SetDParam(0, t->index);
-				SetDParam(1, t->population);
-				DrawString(2, this->width - 2, y, STR_TOWN_DIRECTORY_TOWN);
+					assert(t->xy != INVALID_TILE);
 
-				y += this->townline_height;
-				i++;
-				if (++n == this->vscroll.cap) break; // max number of towns in 1 window
-			}
+					SetDParam(0, t->index);
+					SetDParam(1, t->population);
+					DrawString(r.left + 2, r.right - 2, y, STR_TOWN_DIRECTORY_TOWN);
 
-			SetDParam(0, GetWorldPopulation());
-			DrawString(3, this->width - 3, this->height - 12 + 2, STR_TOWN_POPULATION);
+					y += this->townline_height;
+					if (++n == this->vscroll.cap) break; // max number of towns in 1 window
+				}
+			} break;
+
+			case TDW_EMPTYBOTTOM:
+				SetDParam(0, GetWorldPopulation());
+				DrawString(r.left + 3, r.right - 3, r.top + 2, STR_TOWN_POPULATION);
+				break;
 		}
 	}
 
diff --git a/src/widget.cpp b/src/widget.cpp
index dc8a3598e..390012879 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -223,43 +223,6 @@ int GetWidgetFromPos(const Window *w, int x, int y)
 	return found_index;
 }
 
-/** Distances used in drawing widgets. */
-enum WidgetDrawDistances {
-	WD_IMGBTN_LEFT = 1,         ///< Left offset of the image in the button.
-	WD_IMGBTN_TOP = 1,          ///< Top offset of image in the button.
-
-	WD_INSET_LEFT  = 2,         ///< Left offset of string.
-	WD_INSET_RIGHT = 2,         ///< Right offset of string.
-	WD_INSET_TOP   = 1,         ///< Top offset of string.
-
-	WD_VSCROLLBAR_WIDTH = 12,   ///< Width of a vertical scrollbar.
-
-	WD_HSCROLLBAR_HEIGHT = 12,  ///< Height of a horizontal scrollbar.
-
-	WD_FRAMETEXT_LEFT = 6,      ///< Left offset of the text of the frame.
-	WD_FRAMETEXT_RIGHT = 6,     ///< Right offset of the text of the frame.
-
-	WD_STICKY_WIDTH = 12,       ///< Width of a sticky box widget.
-	WD_STICKY_LEFT = 2,         ///< Left offset of sticky sprite.
-	WD_STICKY_TOP = 3,          ///< Top offset of sticky sprite.
-
-	WD_RESIZE_WIDTH = 12,       ///< Width of a resize box widget.
-	WD_RESIZE_TOP = 3,          ///< Top offset of resize sprite.
-
-	WD_CLOSEBOX_WIDTH = 11,     ///< Width of a close box widget.
-	WD_CLOSEBOX_TOP = 2,        ///< Distance between the top of the close box widget, and the string.
-
-	WD_CAPTION_HEIGHT = 14,     ///< Height of a title bar.
-	WD_CAPTIONTEXT_LEFT = 2,    ///< Offset of the caption text at the left.
-	WD_CAPTIONTEXT_RIGHT = 2,   ///< Offset of the caption text at the right.
-	WD_CAPTIONTEXT_TOP = 2,     ///< Offset of the caption text at the top.
-
-	WD_DROPDOWN_HEIGHT = 12,    ///< Height of a drop down widget.
-	WD_DROPDOWNTEXT_LEFT = 2,   ///< Left offset of the dropdown widget string.
-	WD_DROPDOWNTEXT_RIGHT = 14, ///< Right offset of the dropdown widget string.
-	WD_DROPDOWNTEXT_TOP = 1,    ///< Top offset of the dropdown widget string.
-};
-
 /**
  * Draw frame rectangle.
  * @param left   Left edge of the frame
@@ -327,6 +290,7 @@ static inline void DrawImageButtons(const Rect &r, WidgetType type, Colours colo
  */
 static inline void DrawLabel(const Rect &r, WidgetType type, bool clicked, StringID str)
 {
+	if (str == STR_NULL) return;
 	if ((type & WWT_MASK) == WWT_TEXTBTN_2 && clicked) str++;
 	DrawString(r.left + clicked, r.right + clicked, ((r.top + r.bottom + 1) >> 1) - (FONT_HEIGHT_NORMAL / 2) + clicked, str, TC_FROMSTRING, SA_CENTER);
 }
@@ -582,7 +546,7 @@ static inline void DrawCaption(const Rect &r, Colours colour, Owner owner, Strin
 		GfxFillRect(r.left + 2, r.top + 2, r.right - 2, r.bottom - 2, _colour_gradient[_company_colours[owner]][4]);
 	}
 
-	DrawString(r.left + WD_CAPTIONTEXT_LEFT, r.right - WD_CAPTIONTEXT_RIGHT, r.top + WD_CAPTIONTEXT_TOP, str, TC_FROMSTRING, SA_CENTER);
+	if (str != STR_NULL) DrawString(r.left + WD_CAPTIONTEXT_LEFT, r.right - WD_CAPTIONTEXT_RIGHT, r.top + WD_CAPTIONTEXT_TOP, str, TC_FROMSTRING, SA_CENTER);
 }
 
 static inline void DrawDropdown(const Rect &r, Colours colour, bool clicked, StringID str)
@@ -1001,6 +965,7 @@ inline void NWidgetBase::StoreSizePosition(SizingType sizing, uint x, uint y, ui
 /**
  * @fn void Draw(const Window *w)
  * Draw the widgets of the tree.
+ * The function calls #Window::DrawWidget for each widget with a non-negative index, after the widget itself is painted.
  * @param w Window that owns the tree.
  */
 
@@ -1831,6 +1796,7 @@ void NWidgetBackground::Draw(const Window *w)
 	}
 
 	if (this->child != NULL) this->child->Draw(w);
+	if (this->index >= 0) w->DrawWidget(r, this->index);
 
 	if (this->IsDisabled()) {
 		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, _colour_gradient[this->colour & 0xF][2], FILLRECT_CHECKER);
@@ -2050,6 +2016,7 @@ void NWidgetLeaf::Draw(const Window *w)
 		default:
 			NOT_REACHED();
 	}
+	if (this->index >= 0) w->DrawWidget(r, this->index);
 
 	if (this->IsDisabled()) {
 		GfxFillRect(r.left + 1, r.top + 1, r.right - 1, r.bottom - 1, _colour_gradient[this->colour & 0xF][2], FILLRECT_CHECKER);
diff --git a/src/window_gui.h b/src/window_gui.h
index bc3237ce4..2847bad48 100644
--- a/src/window_gui.h
+++ b/src/window_gui.h
@@ -27,6 +27,57 @@ enum FrameFlags {
 
 DECLARE_ENUM_AS_BIT_SET(FrameFlags);
 
+/** Distances used in drawing widgets. */
+enum WidgetDrawDistances {
+	/* WWT_IMGBTN, WWT_IMGBTN_2 */
+	WD_IMGBTN_LEFT = 1,         ///< Left offset of the image in the button.
+	WD_IMGBTN_TOP = 1,          ///< Top offset of image in the button.
+
+	/* WWT_INSET */
+	WD_INSET_LEFT  = 2,         ///< Left offset of string.
+	WD_INSET_RIGHT = 2,         ///< Right offset of string.
+	WD_INSET_TOP   = 1,         ///< Top offset of string.
+
+	WD_VSCROLLBAR_WIDTH = 12,   ///< Width of a vertical scrollbar.
+
+	WD_HSCROLLBAR_HEIGHT = 12,  ///< Height of a horizontal scrollbar.
+
+	/* FrameRect widgets, all text buttons, panel, editbox */
+	WD_FRAMERECT_LEFT = 2,      ///< Offset at left to draw the frame rectangular area
+	WD_FRAMERECT_RIGHT = 2,     ///< Offset at right to draw the frame rectangular area
+	WD_FRAMERECT_TOP = 1,       ///< Offset at top to draw the frame rectangular area
+	WD_FRAMERECT_BOTTOM = 1,    ///< Offset at bottom to draw the frame rectangular area
+
+	/* WWT_FRAME */
+	WD_FRAMETEXT_LEFT = 6,      ///< Left offset of the text of the frame.
+	WD_FRAMETEXT_RIGHT = 6,     ///< Right offset of the text of the frame.
+
+	/* WWT_STICKYBOX */
+	WD_STICKY_WIDTH = 12,       ///< Width of a sticky box widget.
+	WD_STICKY_LEFT = 2,         ///< Left offset of sticky sprite.
+	WD_STICKY_TOP = 3,          ///< Top offset of sticky sprite.
+
+	/* WWT_RESIZEBOX */
+	WD_RESIZE_WIDTH = 12,       ///< Width of a resize box widget.
+	WD_RESIZE_TOP = 3,          ///< Top offset of resize sprite.
+
+	/* WWT_CLOSEBOX */
+	WD_CLOSEBOX_WIDTH = 11,     ///< Width of a close box widget.
+	WD_CLOSEBOX_TOP = 2,        ///< Distance between the top of the close box widget, and the string.
+
+	/* WWT_CAPTION */
+	WD_CAPTION_HEIGHT = 14,     ///< Height of a title bar.
+	WD_CAPTIONTEXT_LEFT = 2,    ///< Offset of the caption text at the left.
+	WD_CAPTIONTEXT_RIGHT = 2,   ///< Offset of the caption text at the right.
+	WD_CAPTIONTEXT_TOP = 2,     ///< Offset of the caption text at the top.
+
+	/* Dropdown widget. */
+	WD_DROPDOWN_HEIGHT = 12,    ///< Height of a drop down widget.
+	WD_DROPDOWNTEXT_LEFT = 2,   ///< Left offset of the dropdown widget string.
+	WD_DROPDOWNTEXT_RIGHT = 14, ///< Right offset of the dropdown widget string.
+	WD_DROPDOWNTEXT_TOP = 1,    ///< Top offset of the dropdown widget string.
+};
+
 /* wiget.cpp */
 void DrawFrameRect(int left, int top, int right, int bottom, Colours colour, FrameFlags flags);
 
@@ -434,11 +485,20 @@ public:
 	/*** Event handling ***/
 
 	/**
-	 * This window is currently being repainted.
+	 * The window must be repainted.
+	 * @note This method should not change any state, it should only use drawing functions.
 	 */
 	virtual void OnPaint() {}
 
 	/**
+	 * Draw the contents of a nested widget.
+	 * @param r      Rectangle occupied by the widget.
+	 * @param widget Number of the widget to draw.
+	 * @note This method may not change any state, it may only use drawing functions.
+	 */
+	virtual void DrawWidget(const Rect &r, int widget) const {}
+
+	/**
 	 * Called when window gains focus
 	 */
 	virtual void OnFocus() {}