(svn r17372) -Codechange: make the settings, rail and sign GUIs use the scrollbar wrappers

3 files changed, 32 insertions, 34 deletions

diff --git a/src/rail_gui.cpp b/src/rail_gui.cpp
index a44eed5a5..0c97b4d5e 100644
--- a/src/rail_gui.cpp
+++ b/src/rail_gui.cpp
@@ -1024,9 +1024,9 @@ public:
 		if (newstation) {
 			_railstation.station_count = GetNumCustomStations(_railstation.station_class);
 
-			this->vscroll.count = _railstation.station_count;
-			this->vscroll.cap   = GB(this->nested_array[BRSW_NEWST_LIST]->widget_data, MAT_ROW_START, MAT_ROW_BITS);
-			this->vscroll.pos   = Clamp(_railstation.station_type - 2, 0, this->vscroll.count - this->vscroll.cap);
+			this->vscroll.SetCount(_railstation.station_count);
+			this->vscroll.SetCapacity(GB(this->nested_array[BRSW_NEWST_LIST]->widget_data, MAT_ROW_START, MAT_ROW_BITS));
+			this->vscroll.SetPosition(Clamp(_railstation.station_type - 2, 0, this->vscroll.GetCount() - this->vscroll.GetCapacity()));
 		} else {
 			/* New stations are not available, so ensure the default station
 			 * type is 'selected'. */
@@ -1150,7 +1150,7 @@ public:
 
 			case BRSW_NEWST_LIST: {
 				uint y = r.top;
-				for (uint16 i = this->vscroll.pos; i < _railstation.station_count && i < (uint)(this->vscroll.pos + this->vscroll.cap); i++) {
+				for (uint16 i = this->vscroll.GetPosition(); i < _railstation.station_count && this->vscroll.IsVisible(i); i++) {
 					const StationSpec *statspec = GetCustomStationSpec(_railstation.station_class, i);
 
 					StringID str = STR_STATION_CLASS_DFLT;
@@ -1308,8 +1308,8 @@ public:
 				const StationSpec *statspec;
 				int y = (pt.y - this->nested_array[BRSW_NEWST_LIST]->pos_y) / this->line_height;
 
-				if (y >= this->vscroll.cap) return;
-				y += this->vscroll.pos;
+				if (y >= this->vscroll.GetCapacity()) return;
+				y += this->vscroll.GetPosition();
 				if (y >= _railstation.station_count) return;
 
 				/* Check station availability callback */
@@ -1339,8 +1339,8 @@ public:
 
 			this->CheckSelectedSize(GetCustomStationSpec(_railstation.station_class, _railstation.station_type));
 
-			this->vscroll.count = _railstation.station_count;
-			this->vscroll.pos   = _railstation.station_type;
+			this->vscroll.SetCount(_railstation.station_count);
+			this->vscroll.SetPosition(_railstation.station_type);
 		}
 
 		SndPlayFx(SND_15_BEEP);
@@ -1775,24 +1775,24 @@ struct BuildRailWaypointWindow : PickerWindowBase {
 	BuildRailWaypointWindow(const WindowDesc *desc, Window *parent) : PickerWindowBase(parent)
 	{
 		this->InitNested(desc, TRANSPORT_RAIL);
-		this->hscroll.cap = 5;
-		this->hscroll.count = _waypoint_count;
+		this->hscroll.SetCapacity(5);
+		this->hscroll.SetCount(_waypoint_count);
 	};
 
 	virtual void OnPaint()
 	{
-		for (uint i = 0; i < this->hscroll.cap; i++) {
-			this->SetWidgetLoweredState(i + BRWW_WAYPOINT_1, (this->hscroll.pos + i) == _cur_waypoint_type);
+		for (uint i = 0; i < this->hscroll.GetCapacity(); i++) {
+			this->SetWidgetLoweredState(i + BRWW_WAYPOINT_1, (this->hscroll.GetPosition() + i) == _cur_waypoint_type);
 		}
 
 		this->DrawWidgets();
 
-		for (uint i = 0; i < this->hscroll.cap; i++) {
-			if (this->hscroll.pos + i < this->hscroll.count) {
-				const StationSpec *statspec = GetCustomStationSpec(STAT_CLASS_WAYP, this->hscroll.pos + i);
+		for (uint i = 0; i < this->hscroll.GetCapacity(); i++) {
+			if (this->hscroll.GetPosition() + i < this->hscroll.GetCount()) {
+				const StationSpec *statspec = GetCustomStationSpec(STAT_CLASS_WAYP, this->hscroll.GetPosition() + i);
 
 				int bottom = this->nested_array[BRWW_WAYPOINT_1 + i]->pos_y + this->nested_array[BRWW_WAYPOINT_1 + i]->current_y;
-				DrawWaypointSprite(this->nested_array[BRWW_WAYPOINT_1 + i]->pos_x + TILE_PIXELS, bottom - TILE_PIXELS, this->hscroll.pos + i, _cur_railtype);
+				DrawWaypointSprite(this->nested_array[BRWW_WAYPOINT_1 + i]->pos_x + TILE_PIXELS, bottom - TILE_PIXELS, this->hscroll.GetPosition() + i, _cur_railtype);
 
 				if (statspec != NULL &&
 						HasBit(statspec->callbackmask, CBM_STATION_AVAIL) &&
@@ -1811,7 +1811,7 @@ struct BuildRailWaypointWindow : PickerWindowBase {
 			case BRWW_WAYPOINT_3:
 			case BRWW_WAYPOINT_4:
 			case BRWW_WAYPOINT_5: {
-				byte type = widget - BRWW_WAYPOINT_1 + this->hscroll.pos;
+				byte type = widget - BRWW_WAYPOINT_1 + this->hscroll.GetPosition();
 
 				/* Check station availability callback */
 				const StationSpec *statspec = GetCustomStationSpec(STAT_CLASS_WAYP, type);
diff --git a/src/settings_gui.cpp b/src/settings_gui.cpp
index 183f6b51a..9610b833a 100644
--- a/src/settings_gui.cpp
+++ b/src/settings_gui.cpp
@@ -1448,9 +1448,8 @@ struct GameSettingsWindow : Window {
 
 		this->valuewindow_entry = NULL; // No setting entry for which a entry window is opened
 		this->clicked_entry = NULL; // No numeric setting buttons are depressed
-		this->vscroll.pos = 0;
-		this->vscroll.cap = (this->widget[SETTINGSEL_OPTIONSPANEL].bottom - this->widget[SETTINGSEL_OPTIONSPANEL].top - 8) / SETTING_HEIGHT;
-		SetVScrollCount(this, _settings_main_page.Length());
+		this->vscroll.SetCapacity((this->widget[SETTINGSEL_OPTIONSPANEL].bottom - this->widget[SETTINGSEL_OPTIONSPANEL].top - 8) / SETTING_HEIGHT);
+		this->vscroll.SetCount(_settings_main_page.Length());
 
 		this->resize.step_height = SETTING_HEIGHT;
 		this->resize.height = this->height;
@@ -1464,7 +1463,7 @@ struct GameSettingsWindow : Window {
 	{
 		this->DrawWidgets();
 		_settings_main_page.Draw(settings_ptr, SETTINGTREE_LEFT_OFFSET, SETTINGTREE_TOP_OFFSET,
-				this->width - 13, this->vscroll.pos, this->vscroll.pos + this->vscroll.cap);
+				this->width - 13, this->vscroll.GetPosition(), this->vscroll.GetPosition() + this->vscroll.GetCapacity());
 	}
 
 	virtual void OnClick(Point pt, int widget)
@@ -1474,7 +1473,7 @@ struct GameSettingsWindow : Window {
 		int y = pt.y - SETTINGTREE_TOP_OFFSET;  // Shift y coordinate
 		if (y < 0) return;  // Clicked above first entry
 
-		byte btn = this->vscroll.pos + y / SETTING_HEIGHT;  // Compute which setting is selected
+		byte btn = this->vscroll.GetPosition() + y / SETTING_HEIGHT;  // Compute which setting is selected
 		if (y % SETTING_HEIGHT > SETTING_HEIGHT - 2) return;  // Clicked too low at the setting
 
 		uint cur_row = 0;
@@ -1488,7 +1487,7 @@ struct GameSettingsWindow : Window {
 		if ((pe->flags & SEF_KIND_MASK) == SEF_SUBTREE_KIND) {
 			pe->d.sub.folded = !pe->d.sub.folded; // Flip 'folded'-ness of the sub-page
 
-			SetVScrollCount(this, _settings_main_page.Length());
+			this->vscroll.SetCount(_settings_main_page.Length());
 			this->SetDirty();
 			return;
 		}
@@ -1608,8 +1607,7 @@ struct GameSettingsWindow : Window {
 
 	virtual void OnResize(Point delta)
 	{
-		this->vscroll.cap += delta.y / SETTING_HEIGHT;
-		SetVScrollCount(this, _settings_main_page.Length());
+		this->vscroll.UpdateCapacity(delta.y / SETTING_HEIGHT);
 	}
 };
 
diff --git a/src/signs_gui.cpp b/src/signs_gui.cpp
index 1824a7ee3..5c67173fc 100644
--- a/src/signs_gui.cpp
+++ b/src/signs_gui.cpp
@@ -90,7 +90,7 @@ enum SignListWidgets {
 struct SignListWindow : Window, SignList {
 	SignListWindow(const WindowDesc *desc, WindowNumber window_number) : Window(desc, window_number)
 	{
-		this->vscroll.cap = 12;
+		this->vscroll.SetCapacity(12);
 		this->resize.step_height = 10;
 		this->resize.height = this->height - 10 * 7; // minimum if 5 in the list
 
@@ -105,20 +105,20 @@ struct SignListWindow : Window, SignList {
 		BuildSignsList();
 		SortSignsList();
 
-		SetVScrollCount(this, this->signs.Length());
+		this->vscroll.SetCount(this->signs.Length()); // Update the scrollbar
 
-		SetDParam(0, this->vscroll.count);
+		SetDParam(0, this->vscroll.GetCount());
 		this->DrawWidgets();
 
 		/* No signs? */
 		int y = this->widget[SLW_LIST].top + 2; // offset from top of widget
-		if (this->vscroll.count == 0) {
+		if (this->vscroll.GetCount() == 0) {
 			DrawString(this->widget[SLW_LIST].left + 2, this->widget[SLW_LIST].right, y, STR_STATION_LIST_NONE);
 			return;
 		}
 
 		/* Start drawing the signs */
-		for (uint16 i = this->vscroll.pos; i < this->vscroll.cap + this->vscroll.pos && i < this->vscroll.count; i++) {
+		for (uint16 i = this->vscroll.GetPosition(); this->vscroll.IsVisible(i) && i < this->vscroll.GetCount(); i++) {
 			const Sign *si = this->signs[i];
 
 			if (si->owner != OWNER_NONE) DrawCompanyIcon(si->owner, this->widget[SLW_LIST].left + 4, y + 1);
@@ -134,9 +134,9 @@ struct SignListWindow : Window, SignList {
 		if (widget == SLW_LIST) {
 			uint32 id_v = (pt.y - this->widget[SLW_LIST].top - 1) / 10;
 
-			if (id_v >= this->vscroll.cap) return;
-			id_v += this->vscroll.pos;
-			if (id_v >= this->vscroll.count) return;
+			if (id_v >= this->vscroll.GetCapacity()) return;
+			id_v += this->vscroll.GetPosition();
+			if (id_v >= this->vscroll.GetCount()) return;
 
 			const Sign *si = this->signs[id_v];
 			ScrollMainWindowToTile(TileVirtXY(si->x, si->y));
@@ -145,7 +145,7 @@ struct SignListWindow : Window, SignList {
 
 	virtual void OnResize(Point delta)
 	{
-		this->vscroll.cap += delta.y / 10;
+		this->vscroll.UpdateCapacity(delta.y / 10);
 	}
 
 	virtual void OnInvalidateData(int data)