widget.c
author KUDr
Sun, 31 Dec 2006 23:48:04 +0000
branchcustombridgeheads
changeset 5618 a7db50b9f817
parent 5236 e959e132a78e
permissions -rw-r--r--
(svn r7710) [cbh] - Fix: [YAPF] one more assert fixed. Call from the TrainController() added by (r7705) has broken YAPF because it was called when vehicle was already on the next tile (with cbh choice). Before it was always called before the train entered tile with choice.
/* $Id$ */

#include "stdafx.h"
#include "openttd.h"
#include "functions.h"
#include "player.h"
#include "table/sprites.h"
#include "table/strings.h"
#include "window.h"
#include "gfx.h"
#include "viewport.h"

static Point HandleScrollbarHittest(const Scrollbar *sb, int top, int bottom)
{
	Point pt;
	int height, count, pos, cap;

	top += 10;
	bottom -= 9;

	height = (bottom - top);

	pos = sb->pos;
	count = sb->count;
	cap = sb->cap;

	if (count != 0) top += height * pos / count;

	if (cap > count) cap = count;
	if (count != 0) bottom -= (count - pos - cap) * height / count;

	pt.x = top;
	pt.y = bottom - 1;
	return pt;
}

/*****************************************************
 * Special handling for the scrollbar widget type.
 * Handles the special scrolling buttons and other
 * scrolling.
 * Parameters:
 *   w   - Window.
 *   wi  - Pointer to the scrollbar widget.
 *   x   - The X coordinate of the mouse click.
 *   y   - The Y coordinate of the mouse click.
 */

void ScrollbarClickHandler(Window *w, const Widget *wi, int x, int y)
{
	int mi, ma, pos;
	Scrollbar *sb;

	switch (wi->type) {
		case WWT_SCROLLBAR: {
			// vertical scroller
			w->flags4 &= ~WF_HSCROLL;
			w->flags4 &= ~WF_SCROLL2;
			mi = wi->top;
			ma = wi->bottom;
			pos = y;
			sb = &w->vscroll;
			break;
		}
		case WWT_SCROLL2BAR: {
			// 2nd vertical scroller
			w->flags4 &= ~WF_HSCROLL;
			w->flags4 |= WF_SCROLL2;
			mi = wi->top;
			ma = wi->bottom;
			pos = y;
			sb = &w->vscroll2;
			break;
		}
		case  WWT_HSCROLLBAR: {
			// horizontal scroller
			w->flags4 &= ~WF_SCROLL2;
			w->flags4 |= WF_HSCROLL;
			mi = wi->left;
			ma = wi->right;
			pos = x;
			sb = &w->hscroll;
			break;
		}
		default: return; //this should never happen
	}
	if (pos <= mi+9) {
		// Pressing the upper button?
		w->flags4 |= WF_SCROLL_UP;
		if (_scroller_click_timeout == 0) {
			_scroller_click_timeout = 6;
			if (sb->pos != 0) sb->pos--;
		}
		_left_button_clicked = false;
	} else if (pos >= ma-10) {
		// Pressing the lower button?
		w->flags4 |= WF_SCROLL_DOWN;

		if (_scroller_click_timeout == 0) {
			_scroller_click_timeout = 6;
			if ((byte)(sb->pos + sb->cap) < sb->count)
				sb->pos++;
		}
		_left_button_clicked = false;
	} else {
		//
		Point pt = HandleScrollbarHittest(sb, mi, ma);

		if (pos < pt.x) {
			sb->pos = max(sb->pos - sb->cap, 0);
		} else if (pos > pt.y) {
			sb->pos = min(
				sb->pos + sb->cap,
				max(sb->count - sb->cap, 0)
			);
		} else {
			_scrollbar_start_pos = pt.x - mi - 9;
			_scrollbar_size = ma - mi - 23;
			w->flags4 |= WF_SCROLL_MIDDLE;
			_scrolling_scrollbar = true;
			_cursorpos_drag_start = _cursor.pos;
		}
	}

	SetWindowDirty(w);
}

/** Returns the index for the widget located at the given position
 * relative to the window. It includes all widget-corner pixels as well.
 * @param *w Window to look inside
 * @param  x,y Window client coordinates
 * @return A widget index, or -1 if no widget was found.
 */
int GetWidgetFromPos(const Window *w, int x, int y)
{
	uint index;
	int found_index = -1;

	// Go through the widgets and check if we find the widget that the coordinate is
	// inside.
	for (index = 0; index < w->widget_count; index++) {
		const Widget *wi = &w->widget[index];
		if (wi->type == WWT_EMPTY || wi->type == WWT_FRAME) continue;

		if (x >= wi->left && x <= wi->right && y >= wi->top &&  y <= wi->bottom &&
				!IsWindowWidgetHidden(w, index)) {
			found_index = index;
		}
	}

	return found_index;
}


void DrawFrameRect(int left, int top, int right, int bottom, int ctab, FrameFlags flags)
{
	uint dark         = _colour_gradient[ctab][3];
	uint medium_dark  = _colour_gradient[ctab][5];
	uint medium_light = _colour_gradient[ctab][6];
	uint light        = _colour_gradient[ctab][7];

	if (flags & FR_TRANSPARENT) {
		GfxFillRect(left, top, right, bottom, 0x322 | USE_COLORTABLE);
	} else {
		uint interior;

		if (flags & FR_LOWERED) {
			GfxFillRect(left,     top,     left,  bottom,     dark);
			GfxFillRect(left + 1, top,     right, top,        dark);
			GfxFillRect(right,    top + 1, right, bottom - 1, light);
			GfxFillRect(left + 1, bottom,  right, bottom,     light);
			interior = (flags & FR_DARKENED ? medium_dark : medium_light);
		} else {
			GfxFillRect(left,     top,    left,      bottom - 1, light);
			GfxFillRect(left + 1, top,    right - 1, top,        light);
			GfxFillRect(right,    top,    right,     bottom - 1, dark);
			GfxFillRect(left,     bottom, right,     bottom,     dark);
			interior = medium_dark;
		}
		if (!(flags & FR_BORDERONLY)) {
			GfxFillRect(left + 1, top + 1, right - 1, bottom - 1, interior);
		}
	}
}


void DrawWindowWidgets(const Window *w)
{
	const DrawPixelInfo* dpi = _cur_dpi;
	Rect r;
	uint i;

	for (i = 0; i < w->widget_count; i++) {
		const Widget *wi = &w->widget[i];
		bool clicked = IsWindowWidgetLowered(w, i);

		if (dpi->left > (r.right=/*w->left + */wi->right) ||
				dpi->left + dpi->width <= (r.left=wi->left/* + w->left*/) ||
				dpi->top > (r.bottom=/*w->top +*/ wi->bottom) ||
				dpi->top + dpi->height <= (r.top = /*w->top +*/ wi->top) ||
				IsWindowWidgetHidden(w, i)) {
			continue;
		}

		switch (wi->type & WWT_MASK) {
		case WWT_IMGBTN:
		case WWT_IMGBTN_2: {
			int img = wi->data;
			assert(img != 0);
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);

			/* show different image when clicked for WWT_IMGBTN_2 */
			if ((wi->type & WWT_MASK) == WWT_IMGBTN_2 && clicked) img++;
			DrawSprite(img, r.left + 1 + clicked, r.top + 1 + clicked);
			goto draw_default;
		}

		case WWT_PANEL: {
			assert(wi->data == 0);
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			goto draw_default;
		}

		case WWT_TEXTBTN:
		case WWT_TEXTBTN_2: {
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			}
		/* fall through */

		case WWT_LABEL: {
			StringID str = wi->data;

			if ((wi->type & WWT_MASK) == WWT_TEXTBTN_2 && clicked) str++;

			DrawStringCentered(((r.left + r.right + 1) >> 1) + clicked, ((r.top + r.bottom + 1) >> 1) - 5 + clicked, str, 0);
			goto draw_default;
		}

		case WWT_INSET: {
			StringID str = wi->data;
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, FR_LOWERED | FR_DARKENED);

			if (str != STR_NULL) DrawStringTruncated(r.left + 2, r.top + 1, str, 0, r.right - r.left - 10);
			goto draw_default;
		}

		case WWT_MATRIX: {
			int c, d, ctr;
			int x, amt1, amt2;
			int color;

			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);

			c = GB(wi->data, 0, 8);
			amt1 = (wi->right - wi->left + 1) / c;

			d = GB(wi->data, 8, 8);
			amt2 = (wi->bottom - wi->top + 1) / d;

			color = _colour_gradient[wi->color & 0xF][6];

			x = r.left;
			for (ctr = c; ctr > 1; ctr--) {
				x += amt1;
				GfxFillRect(x, r.top + 1, x, r.bottom - 1, color);
			}

			x = r.top;
			for (ctr = d; ctr > 1; ctr--) {
				x += amt2;
				GfxFillRect(r.left + 1, x, r.right - 1, x, color);
			}

			color = _colour_gradient[wi->color&0xF][4];

			x = r.left - 1;
			for (ctr = c; ctr > 1; ctr--) {
				x += amt1;
				GfxFillRect(x, r.top + 1, x, r.bottom - 1, color);
			}

			x = r.top - 1;
			for (ctr = d; ctr > 1; ctr--) {
				x += amt2;
				GfxFillRect(r.left+1, x, r.right-1, x, color);
			}

			goto draw_default;
		}

		// vertical scrollbar
		case WWT_SCROLLBAR: {
			Point pt;
			int c1,c2;

			assert(r.right - r.left == 11); // XXX - to ensure the same sizes are used everywhere!

			// draw up/down buttons
			clicked = ((w->flags4 & (WF_SCROLL_UP | WF_HSCROLL | WF_SCROLL2)) == WF_SCROLL_UP);
			DrawFrameRect(r.left, r.top, r.right, r.top + 9, wi->color, (clicked) ? FR_LOWERED : 0);
			DoDrawString(UPARROW, r.left + 2 + clicked, r.top + clicked, 0x10);

			clicked = (((w->flags4 & (WF_SCROLL_DOWN | WF_HSCROLL | WF_SCROLL2)) == WF_SCROLL_DOWN));
			DrawFrameRect(r.left, r.bottom - 9, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			DoDrawString(DOWNARROW, r.left + 2 + clicked, r.bottom - 9 + clicked, 0x10);

			c1 = _colour_gradient[wi->color&0xF][3];
			c2 = _colour_gradient[wi->color&0xF][7];

			// draw "shaded" background
			GfxFillRect(r.left, r.top+10, r.right, r.bottom-10, c2);
			GfxFillRect(r.left, r.top+10, r.right, r.bottom-10, c1 | PALETTE_MODIFIER_GREYOUT);

			// draw shaded lines
			GfxFillRect(r.left+2, r.top+10, r.left+2, r.bottom-10, c1);
			GfxFillRect(r.left+3, r.top+10, r.left+3, r.bottom-10, c2);
			GfxFillRect(r.left+7, r.top+10, r.left+7, r.bottom-10, c1);
			GfxFillRect(r.left+8, r.top+10, r.left+8, r.bottom-10, c2);

			pt = HandleScrollbarHittest(&w->vscroll, r.top, r.bottom);
			DrawFrameRect(r.left, pt.x, r.right, pt.y, wi->color, (w->flags4 & (WF_SCROLL_MIDDLE | WF_HSCROLL | WF_SCROLL2)) == WF_SCROLL_MIDDLE ? FR_LOWERED : 0);
			break;
		}
		case WWT_SCROLL2BAR: {
			Point pt;
			int c1,c2;

			assert(r.right - r.left == 11); // XXX - to ensure the same sizes are used everywhere!

			// draw up/down buttons
			clicked = ((w->flags4 & (WF_SCROLL_UP | WF_HSCROLL | WF_SCROLL2)) == (WF_SCROLL_UP | WF_SCROLL2));
			DrawFrameRect(r.left, r.top, r.right, r.top + 9, wi->color,  (clicked) ? FR_LOWERED : 0);
			DoDrawString(UPARROW, r.left + 2 + clicked, r.top + clicked, 0x10);

			clicked = ((w->flags4 & (WF_SCROLL_DOWN | WF_HSCROLL | WF_SCROLL2)) == (WF_SCROLL_DOWN | WF_SCROLL2));
			DrawFrameRect(r.left, r.bottom - 9, r.right, r.bottom, wi->color,  (clicked) ? FR_LOWERED : 0);
			DoDrawString(DOWNARROW, r.left + 2 + clicked, r.bottom - 9 + clicked, 0x10);

			c1 = _colour_gradient[wi->color&0xF][3];
			c2 = _colour_gradient[wi->color&0xF][7];

			// draw "shaded" background
			GfxFillRect(r.left, r.top+10, r.right, r.bottom-10, c2);
			GfxFillRect(r.left, r.top+10, r.right, r.bottom-10, c1 | PALETTE_MODIFIER_GREYOUT);

			// draw shaded lines
			GfxFillRect(r.left+2, r.top+10, r.left+2, r.bottom-10, c1);
			GfxFillRect(r.left+3, r.top+10, r.left+3, r.bottom-10, c2);
			GfxFillRect(r.left+7, r.top+10, r.left+7, r.bottom-10, c1);
			GfxFillRect(r.left+8, r.top+10, r.left+8, r.bottom-10, c2);

			pt = HandleScrollbarHittest(&w->vscroll2, r.top, r.bottom);
			DrawFrameRect(r.left, pt.x, r.right, pt.y, wi->color, (w->flags4 & (WF_SCROLL_MIDDLE | WF_HSCROLL | WF_SCROLL2)) == (WF_SCROLL_MIDDLE | WF_SCROLL2) ? FR_LOWERED : 0);
			break;
		}

		// horizontal scrollbar
		case WWT_HSCROLLBAR: {
			Point pt;
			int c1,c2;

			assert(r.bottom - r.top == 11); // XXX - to ensure the same sizes are used everywhere!

			clicked = ((w->flags4 & (WF_SCROLL_UP | WF_HSCROLL)) == (WF_SCROLL_UP | WF_HSCROLL));
			DrawFrameRect(r.left, r.top, r.left + 9, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			DrawSprite(SPR_ARROW_LEFT, r.left + 1 + clicked, r.top + 1 + clicked);

			clicked = ((w->flags4 & (WF_SCROLL_DOWN | WF_HSCROLL)) == (WF_SCROLL_DOWN | WF_HSCROLL));
			DrawFrameRect(r.right-9, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			DrawSprite(SPR_ARROW_RIGHT, r.right - 8 + clicked, r.top + 1 + clicked);

			c1 = _colour_gradient[wi->color&0xF][3];
			c2 = _colour_gradient[wi->color&0xF][7];

			// draw "shaded" background
			GfxFillRect(r.left+10, r.top, r.right-10, r.bottom, c2);
			GfxFillRect(r.left+10, r.top, r.right-10, r.bottom, c1 | PALETTE_MODIFIER_GREYOUT);

			// draw shaded lines
			GfxFillRect(r.left+10, r.top+2, r.right-10, r.top+2, c1);
			GfxFillRect(r.left+10, r.top+3, r.right-10, r.top+3, c2);
			GfxFillRect(r.left+10, r.top+7, r.right-10, r.top+7, c1);
			GfxFillRect(r.left+10, r.top+8, r.right-10, r.top+8, c2);

			// draw actual scrollbar
			pt = HandleScrollbarHittest(&w->hscroll, r.left, r.right);
			DrawFrameRect(pt.x, r.top, pt.y, r.bottom, wi->color, (w->flags4 & (WF_SCROLL_MIDDLE | WF_HSCROLL)) == (WF_SCROLL_MIDDLE | WF_HSCROLL) ? FR_LOWERED : 0);

			break;
		}

		case WWT_FRAME: {
			int c1,c2;
			int x2 = r.left; // by default the left side is the left side of the widget

			if (wi->data != 0) x2 = DrawString(r.left + 6, r.top, wi->data, 0);

			c1 = _colour_gradient[wi->color][3];
			c2 = _colour_gradient[wi->color][7];

			//Line from upper left corner to start of text
			GfxFillRect(r.left, r.top+4, r.left+4,r.top+4, c1);
			GfxFillRect(r.left+1, r.top+5, r.left+4,r.top+5, c2);

			// Line from end of text to upper right corner
			GfxFillRect(x2, r.top+4, r.right-1,r.top+4,c1);
			GfxFillRect(x2, r.top+5, r.right-2,r.top+5,c2);

			// Line from upper left corner to bottom left corner
			GfxFillRect(r.left, r.top+5, r.left, r.bottom-1, c1);
			GfxFillRect(r.left+1, r.top+6, r.left+1, r.bottom-2, c2);

			//Line from upper right corner to bottom right corner
			GfxFillRect(r.right-1, r.top+5, r.right-1, r.bottom-2, c1);
			GfxFillRect(r.right, r.top+4, r.right, r.bottom-1, c2);

			GfxFillRect(r.left+1, r.bottom-1, r.right-1, r.bottom-1, c1);
			GfxFillRect(r.left, r.bottom, r.right, r.bottom, c2);

			goto draw_default;
		}

		case WWT_STICKYBOX: {
			assert(r.right - r.left == 11); // XXX - to ensure the same sizes are used everywhere!

			clicked = !!(w->flags4 & WF_STICKY);
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			DrawSprite((clicked) ? SPR_PIN_UP : SPR_PIN_DOWN, r.left + 2 + clicked, r.top + 3 + clicked);
			break;
		}

		case WWT_RESIZEBOX: {
			assert(r.right - r.left == 11); // XXX - to ensure the same sizes are used everywhere!

			clicked = !!(w->flags4 & WF_SIZING);
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, (clicked) ? FR_LOWERED : 0);
			DrawSprite(SPR_WINDOW_RESIZE, r.left + 3 + clicked, r.top + 3 + clicked);
			break;
		}

		case WWT_CLOSEBOX: {
			assert(r.right - r.left == 10); // ensure the same sizes are used everywhere

			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, 0);
			DrawString(r.left + 2, r.top + 2, STR_00C5, 0);
			break;
		}

		case WWT_CAPTION: {
			assert(r.bottom - r.top == 13); // XXX - to ensure the same sizes are used everywhere!
			DrawFrameRect(r.left, r.top, r.right, r.bottom, wi->color, FR_BORDERONLY);
			DrawFrameRect(r.left+1, r.top+1, r.right-1, r.bottom-1, wi->color, (w->caption_color == 0xFF) ? FR_LOWERED | FR_DARKENED : FR_LOWERED | FR_DARKENED | FR_BORDERONLY);

			if (w->caption_color != 0xFF) {
				GfxFillRect(r.left+2, r.top+2, r.right-2, r.bottom-2, _colour_gradient[_player_colors[w->caption_color]][4]);
			}

			DrawStringCenteredTruncated(r.left + 2, r.right - 2, r.top+2, wi->data, 0x84);
draw_default:;
			if (IsWindowWidgetDisabled(w, i)) {
				GfxFillRect(r.left+1, r.top+1, r.right-1, r.bottom-1, _colour_gradient[wi->color&0xF][2] | PALETTE_MODIFIER_GREYOUT);
			}
		}
		}
	}


	if (w->flags4 & WF_WHITE_BORDER_MASK) {
		//DrawFrameRect(w->left, w->top, w->left + w->width-1, w->top+w->height-1, 0xF, 0x10);
		DrawFrameRect(0, 0, w->width-1, w->height-1, 0xF, FR_BORDERONLY);
	}

}

static const Widget _dropdown_menu_widgets[] = {
{      WWT_PANEL,   RESIZE_NONE,     0,     0, 0,     0, 0, 0x0, STR_NULL},
{  WWT_SCROLLBAR,   RESIZE_NONE,     0,     0, 0,     0, 0, 0x0, STR_0190_SCROLL_BAR_SCROLLS_LIST},
{   WIDGETS_END},
};

static int GetDropdownItem(const Window *w)
{
	byte item, counter;
	int y;

	if (GetWidgetFromPos(w, _cursor.pos.x - w->left, _cursor.pos.y - w->top) < 0)
		return -1;

	y = _cursor.pos.y - w->top - 2 + w->vscroll.pos * 10;

	if (y < 0)
		return - 1;

	item = y / 10;
	if (item >= WP(w,dropdown_d).num_items || (HASBIT(WP(w,dropdown_d).disabled_state, item) && !HASBIT(WP(w,dropdown_d).hidden_state, item)) || WP(w,dropdown_d).items[item] == 0)
		return - 1;

	// Skip hidden items -- +1 for each hidden item before the clicked item.
	for (counter = 0; item >= counter; ++counter)
		if (HASBIT(WP(w,dropdown_d).hidden_state, counter)) item++;

	return item;
}

static void DropdownMenuWndProc(Window *w, WindowEvent *e)
{
	int item;

	switch (e->event) {
		case WE_PAINT: {
			int x,y,i,sel;
			int width, height;

			DrawWindowWidgets(w);

			x = 1;
			y = 2 - w->vscroll.pos * 10;

			sel    = WP(w,dropdown_d).selected_index;
			width  = w->widget[0].right - 3;
			height = w->widget[0].bottom - 3;

			for (i = 0; WP(w,dropdown_d).items[i] != INVALID_STRING_ID; i++, sel--) {
				if (HASBIT(WP(w,dropdown_d).hidden_state, i)) continue;

				if (y >= 0 && y <= height) {
					if (WP(w,dropdown_d).items[i] != STR_NULL) {
						if (sel == 0) GfxFillRect(x + 1, y, x + width, y + 9, 0);
						DrawStringTruncated(x + 2, y, WP(w,dropdown_d).items[i], sel == 0 ? 12 : 16, x + width);

						if (HASBIT(WP(w,dropdown_d).disabled_state, i)) {
							GfxFillRect(x, y, x + width, y + 9,
								PALETTE_MODIFIER_GREYOUT | _colour_gradient[_dropdown_menu_widgets[0].color][5]
							);
						}
					} else {
						int c1 = _colour_gradient[_dropdown_menu_widgets[0].color][3];
						int c2 = _colour_gradient[_dropdown_menu_widgets[0].color][7];

						GfxFillRect(x + 1, y + 3, x + w->width - 5, y + 3, c1);
						GfxFillRect(x + 1, y + 4, x + w->width - 5, y + 4, c2);
					}
				}
				y += 10;
			}
		} break;

		case WE_CLICK: {
			if (e->we.click.widget != 0) break;
			item = GetDropdownItem(w);
			if (item >= 0) {
				WP(w,dropdown_d).click_delay = 4;
				WP(w,dropdown_d).selected_index = item;
				SetWindowDirty(w);
			}
		} break;

		case WE_MOUSELOOP: {
			Window *w2 = FindWindowById(WP(w,dropdown_d).parent_wnd_class, WP(w,dropdown_d).parent_wnd_num);
			if (w2 == NULL) {
				DeleteWindow(w);
				return;
			}

			if (WP(w,dropdown_d).click_delay != 0 && --WP(w,dropdown_d).click_delay == 0) {
				WindowEvent e;
				e.event = WE_DROPDOWN_SELECT;
				e.we.dropdown.button = WP(w,dropdown_d).parent_button;
				e.we.dropdown.index  = WP(w,dropdown_d).selected_index;
				w2->wndproc(w2, &e);
				DeleteWindow(w);
				return;
			}

			if (WP(w,dropdown_d).drag_mode) {
				item = GetDropdownItem(w);

				if (!_left_button_clicked) {
					WP(w,dropdown_d).drag_mode = false;
					if (item < 0) return;
					WP(w,dropdown_d).click_delay = 2;
				} else {
					if (item < 0) return;
				}

				WP(w,dropdown_d).selected_index = item;
				SetWindowDirty(w);
			}
		} break;

		case WE_DESTROY: {
			Window *w2 = FindWindowById(WP(w,dropdown_d).parent_wnd_class, WP(w,dropdown_d).parent_wnd_num);
			if (w2 != NULL) {
				RaiseWindowWidget(w2, WP(w,dropdown_d).parent_button);
				InvalidateWidget(w2, WP(w,dropdown_d).parent_button);
			}
		} break;
	}
}

void ShowDropDownMenu(Window *w, const StringID *strings, int selected, int button, uint32 disabled_mask, uint32 hidden_mask)
{
	int i;
	const Widget *wi;
	Window *w2;
	const Window *w3;
	bool is_dropdown_menu_shown = IsWindowWidgetLowered(w, button);
	int top, height;
	int screen_top, screen_bottom;
	bool scroll = false;

	DeleteWindowById(WC_DROPDOWN_MENU, 0);

	if (is_dropdown_menu_shown) return;

	LowerWindowWidget(w, button);

	InvalidateWidget(w, button);

	for (i = 0; strings[i] != INVALID_STRING_ID; i++) {}
	if (i == 0) return;

	wi = &w->widget[button];

	if (hidden_mask != 0) {
		uint j;

		for (j = 0; strings[j] != INVALID_STRING_ID; j++) {
			if (HASBIT(hidden_mask, j)) i--;
		}
	}

	/* The preferred position is just below the dropdown calling widget */
	top = w->top + wi->bottom + 2;
	height = i * 10 + 4;

	w3 = FindWindowById(WC_STATUS_BAR, 0);
	screen_bottom = w3 == NULL ? _screen.height : w3->top;

	/* Check if the dropdown will fully fit below the widget */
	if (top + height >= screen_bottom) {
		w3 = FindWindowById(WC_MAIN_TOOLBAR, 0);
		screen_top = w3 == NULL ? 0 : w3->top + w3->height;

		/* If not, check if it will fit above the widget */
		if (w->top + wi->top - height - 1 > screen_top) {
			top = w->top + wi->top - height - 1;
		} else {
			/* ... and lastly if it won't, enable the scroll bar and fit the
			 * list in below the widget */
			int rows = (screen_bottom - 4 - top) / 10;
			height = rows * 10 + 4;
			scroll = true;
		}
	}

	w2 = AllocateWindow(
		w->left + wi[-1].left + 1,
		top,
		wi->right - wi[-1].left + 1,
		height,
		DropdownMenuWndProc,
		WC_DROPDOWN_MENU,
		_dropdown_menu_widgets);

	w2->widget[0].color = wi->color;
	w2->widget[0].right = wi->right - wi[-1].left;
	w2->widget[0].bottom = height - 1;

	SetWindowWidgetHiddenState(w2, 1, !scroll);

	if (scroll) {
		/* We're scrolling, so enable the scroll bar and shrink the list by
		 * the scrollbar's width */
		w2->widget[1].color  = wi->color;
		w2->widget[1].right  = w2->widget[0].right;
		w2->widget[1].left   = w2->widget[1].right - 11;
		w2->widget[1].bottom = height - 1;
		w2->widget[0].right -= 12;

		w2->vscroll.cap   = (height - 4) / 10;
		w2->vscroll.count = i;
	}

	w2->desc_flags = WDF_DEF_WIDGET;
	w2->flags4 &= ~WF_WHITE_BORDER_MASK;

	WP(w2,dropdown_d).disabled_state = disabled_mask;
	WP(w2,dropdown_d).hidden_state = hidden_mask;

	WP(w2,dropdown_d).parent_wnd_class = w->window_class;
	WP(w2,dropdown_d).parent_wnd_num = w->window_number;
	WP(w2,dropdown_d).parent_button = button;

	WP(w2,dropdown_d).num_items = i;
	WP(w2,dropdown_d).selected_index = selected;
	WP(w2,dropdown_d).items = strings;

	WP(w2,dropdown_d).click_delay = 0;
	WP(w2,dropdown_d).drag_mode = true;
}