widget.c
author peter1138
Sun, 01 Oct 2006 12:00:32 +0000
changeset 4694 c917a3ad0dd2
parent 4634 07699ac2bf37
child 4719 fc6e14219f72
permissions -rw-r--r--
(svn r6601) - Codechange: Support cargo subtypes in the refit window. The refit window has been altered to support resizing and scrolling. Note that the cargo subtype isn't yet passed for actual refitting yet. (Based on mart3p's patch)
/* $Id$ */

#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)
{
	const Widget *wi;
	int index, found_index = -1;

	// Go through the widgets and check if we find the widget that the coordinate is
	// inside.
	for (index = 0,wi = w->widget; wi->type != WWT_LAST; index++, wi++) {
		if (wi->type == WWT_EMPTY || wi->type == WWT_FRAME) continue;

		if (x >= wi->left && x <= wi->right && y >= wi->top &&  y <= wi->bottom &&
				!HASBIT(w->hidden_state,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 Widget *wi;
	const DrawPixelInfo* dpi = _cur_dpi;
	Rect r;
	uint32 cur_click, cur_disabled, cur_hidden;

	wi = w->widget;

	cur_click = w->click_state;
	cur_disabled = w->disabled_state;
	cur_hidden = w->hidden_state;

	do {
		bool clicked = (cur_click & 1);

		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) ||
				cur_hidden & 1) {
			continue;
		}

		switch (wi->type & WWT_MASK) {
		case WWT_PANEL: /* WWT_IMGBTN */
		case WWT_PANEL_2: {
			int img = wi->data;

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

			if (img != 0) { // has an image
				// show diff image when clicked
				if ((wi->type & WWT_MASK) == WWT_PANEL_2 && clicked) img++;

				DrawSprite(img, r.left + 1 + clicked, r.top + 1 + clicked);
			}
			goto draw_default;
		}

		case WWT_TEXTBTN: /* WWT_TEXTBTN */
		case WWT_4: {
			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_4 && clicked) str++;

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

		case WWT_6: {
			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]);
			}

			DrawStringCentered( (r.left+r.right+1)>>1, r.top+2, wi->data, 0x84);
draw_default:;
			if (cur_disabled & 1) {
				GfxFillRect(r.left+1, r.top+1, r.right-1, r.bottom-1, _colour_gradient[wi->color&0xF][2] | PALETTE_MODIFIER_GREYOUT);
			}
		}
		}
	} while (cur_click>>=1, cur_disabled>>=1, cur_hidden >>= 1, (++wi)->type != WWT_LAST);


	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_IMGBTN,   RESIZE_NONE,     0,     0, 0,     0, 0, 0x0, STR_NULL},
{   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;

	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;

			DrawWindowWidgets(w);

			x = 1;
			y = 2;
			sel    = WP(w,dropdown_d).selected_index;

			for (i = 0; WP(w,dropdown_d).items[i] != INVALID_STRING_ID; i++) {
				if (HASBIT(WP(w,dropdown_d).hidden_state, i)) {
					sel--;
					continue;
				}
				if (WP(w,dropdown_d).items[i] != STR_NULL) {
					if (sel == 0) GfxFillRect(x + 1, y, x + w->width - 4, y + 9, 0);
					DrawStringTruncated(x + 2, y, WP(w,dropdown_d).items[i], sel == 0 ? 12 : 16, w->width - 4);

					if (HASBIT(WP(w,dropdown_d).disabled_state, i)) {
						GfxFillRect(x, y, x + w->width - 3, 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;
				sel--;
			}
		} break;

		case WE_CLICK: {
			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) {
				CLRBIT(w2->click_state, 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)
{
	WindowNumber num;
	WindowClass cls;
	int i;
	const Widget *wi;
	Window *w2;
	uint32 old_click_state = w->click_state;

	cls = w->window_class;
	num = w->window_number;
	DeleteWindowById(WC_DROPDOWN_MENU, 0);
	w = FindWindowById(cls, num);

	if (HASBIT(old_click_state, button)) return;

	SETBIT(w->click_state, 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--;
		}
	}

	w2 = AllocateWindow(
		w->left + wi[-1].left + 1,
		w->top + wi->bottom + 2,
		wi->right - wi[-1].left + 1,
		i * 10 + 4,
		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 = i * 10 + 3;

	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;
}