485 

   486 static const Widget _dropdown_menu_widgets[] = {

   487 {      WWT_PANEL,   RESIZE_NONE,     0,     0, 0,     0, 0, 0x0, STR_NULL},

   488 {  WWT_SCROLLBAR,   RESIZE_NONE,     0,     0, 0,     0, 0, 0x0, STR_0190_SCROLL_BAR_SCROLLS_LIST},

   489 {   WIDGETS_END},

   490 };

   491 

   492 static int GetDropdownItem(const Window *w)

   493 {

   494 	byte item, counter;

   495 	int y;

   496 

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

   498 		return -1;

   499 

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

   501 

   502 	if (y < 0)

   503 		return - 1;

   504 

   505 	item = y / 10;

   506 	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)

   507 		return - 1;

   508 

   509 	/* Skip hidden items -- +1 for each hidden item before the clicked item. */

   510 	for (counter = 0; item >= counter; ++counter)

   511 		if (HasBit(WP(w, dropdown_d).hidden_state, counter)) item++;

   512 

   513 	return item;

   514 }

   515 

   516 static void DropdownMenuWndProc(Window *w, WindowEvent *e)

   517 {

   518 	int item;

   519 

   520 	switch (e->event) {

   521 		case WE_PAINT: {

   522 			int x,y,i,sel;

   523 			int width, height;

   524 

   525 			DrawWindowWidgets(w);

   526 

   527 			x = 1;

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

   529 

   530 			sel    = WP(w, dropdown_d).selected_index;

   531 			width  = w->widget[0].right - 3;

   532 			height = w->widget[0].bottom - 3;

   533 

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

   535 				if (HasBit(WP(w, dropdown_d).hidden_state, i)) continue;

   536 

   537 				if (y >= 0 && y <= height) {

   538 					if (WP(w, dropdown_d).items[i] != STR_NULL) {

   539 						if (sel == 0) GfxFillRect(x + 1, y, x + width, y + 9, 0);

   540 						DrawStringTruncated(x + 2, y, WP(w, dropdown_d).items[i], sel == 0 ? TC_WHITE : TC_BLACK, x + width);

   541 

   542 						if (HasBit(WP(w, dropdown_d).disabled_state, i)) {

   543 							GfxFillRect(x, y, x + width, y + 9,

   544 								(1 << PALETTE_MODIFIER_GREYOUT) | _colour_gradient[_dropdown_menu_widgets[0].color][5]

   545 							);

   546 						}

   547 					} else {

   548 						int c1 = _colour_gradient[_dropdown_menu_widgets[0].color][3];

   549 						int c2 = _colour_gradient[_dropdown_menu_widgets[0].color][7];

   550 

   551 						GfxFillRect(x + 1, y + 3, x + w->width - 5, y + 3, c1);

   552 						GfxFillRect(x + 1, y + 4, x + w->width - 5, y + 4, c2);

   553 					}

   554 				}

   555 				y += 10;

   556 			}

   557 		} break;

   558 

   559 		case WE_CLICK: {

   560 			if (e->we.click.widget != 0) break;

   561 			item = GetDropdownItem(w);

   562 			if (item >= 0) {

   563 				WP(w, dropdown_d).click_delay = 4;

   564 				WP(w, dropdown_d).selected_index = item;

   565 				SetWindowDirty(w);

   566 			}

   567 		} break;

   568 

   569 		case WE_MOUSELOOP: {

   570 			Window *w2 = FindWindowById(WP(w, dropdown_d).parent_wnd_class, WP(w,dropdown_d).parent_wnd_num);

   571 			if (w2 == NULL) {

   572 				DeleteWindow(w);

   573 				return;

   574 			}

   575 

   576 			if (WP(w, dropdown_d).click_delay != 0 && --WP(w,dropdown_d).click_delay == 0) {

   577 				WindowEvent e;

   578 				e.event = WE_DROPDOWN_SELECT;

   579 				e.we.dropdown.button = WP(w, dropdown_d).parent_button;

   580 				e.we.dropdown.index  = WP(w, dropdown_d).selected_index;

   581 				w2->wndproc(w2, &e);

   582 				DeleteWindow(w);

   583 				return;

   584 			}

   585 

   586 			if (WP(w, dropdown_d).drag_mode) {

   587 				item = GetDropdownItem(w);

   588 

   589 				if (!_left_button_clicked) {

   590 					WP(w, dropdown_d).drag_mode = false;

   591 					if (item < 0) return;

   592 					WP(w, dropdown_d).click_delay = 2;

   593 				} else {

   594 					if (item < 0) return;

   595 				}

   596 

   597 				WP(w, dropdown_d).selected_index = item;

   598 				SetWindowDirty(w);

   599 			}

   600 		} break;

   601 

   602 		case WE_DESTROY: {

   603 			Window *w2 = FindWindowById(WP(w, dropdown_d).parent_wnd_class, WP(w,dropdown_d).parent_wnd_num);

   604 			if (w2 != NULL) {

   605 				w2->RaiseWidget(WP(w, dropdown_d).parent_button);

   606 				w2->InvalidateWidget(WP(w, dropdown_d).parent_button);

   607 			}

   608 		} break;

   609 	}

   610 }

   611 

   612 void ShowDropDownMenu(Window *w, const StringID *strings, int selected, int button, uint32 disabled_mask, uint32 hidden_mask)

   613 {

   614 	int i;

   615 	const Widget *wi;

   616 	Window *w2;

   617 	const Window *w3;

   618 	bool is_dropdown_menu_shown = w->IsWidgetLowered(button);

   619 	int top, height;

   620 	int screen_top, screen_bottom;

   621 	bool scroll = false;

   622 

   623 	DeleteWindowById(WC_DROPDOWN_MENU, 0);

   624 

   625 	if (is_dropdown_menu_shown) return;

   626 

   627 	w->LowerWidget(button);

   628 

   629 	w->InvalidateWidget(button);

   630 

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

   632 	if (i == 0) return;

   633 

   634 	wi = &w->widget[button];

   635 

   636 	if (hidden_mask != 0) {

   637 		uint j;

   638 

   639 		for (j = 0; strings[j] != INVALID_STRING_ID; j++) {

   640 			if (HasBit(hidden_mask, j)) i--;

   641 		}

   642 	}

   643 

   644 	/* The preferred position is just below the dropdown calling widget */

   645 	top = w->top + wi->bottom + 2;

   646 	height = i * 10 + 4;

   647 

   648 	w3 = FindWindowById(WC_STATUS_BAR, 0);

   649 	screen_bottom = w3 == NULL ? _screen.height : w3->top;

   650 

   651 	/* Check if the dropdown will fully fit below the widget */

   652 	if (top + height >= screen_bottom) {

   653 		w3 = FindWindowById(WC_MAIN_TOOLBAR, 0);

   654 		screen_top = w3 == NULL ? 0 : w3->top + w3->height;

   655 

   656 		/* If not, check if it will fit above the widget */

   657 		if (w->top + wi->top - height - 1 > screen_top) {

   658 			top = w->top + wi->top - height - 1;

   659 		} else {

   660 			/* ... and lastly if it won't, enable the scroll bar and fit the

   661 			 * list in below the widget */

   662 			int rows = (screen_bottom - 4 - top) / 10;

   663 			height = rows * 10 + 4;

   664 			scroll = true;

   665 		}

   666 	}

   667 

   668 	w2 = AllocateWindow(

   669 		w->left + wi[-1].left + 1,

   670 		top,

   671 		wi->right - wi[-1].left + 1,

   672 		height,

   673 		DropdownMenuWndProc,

   674 		WC_DROPDOWN_MENU,

   675 		_dropdown_menu_widgets);

   676 

   677 	w2->widget[0].color = wi->color;

   678 	w2->widget[0].right = wi->right - wi[-1].left;

   679 	w2->widget[0].bottom = height - 1;

   680 

   681 	w2->SetWidgetHiddenState(1, !scroll);

   682 

   683 	if (scroll) {

   684 		/* We're scrolling, so enable the scroll bar and shrink the list by

   685 		 * the scrollbar's width */

   686 		w2->widget[1].color  = wi->color;

   687 		w2->widget[1].right  = w2->widget[0].right;

   688 		w2->widget[1].left   = w2->widget[1].right - 11;

   689 		w2->widget[1].bottom = height - 1;

   690 		w2->widget[0].right -= 12;

   691 

   692 		w2->vscroll.cap   = (height - 4) / 10;

   693 		w2->vscroll.count = i;

   694 	}

   695 

   696 	w2->desc_flags = WDF_DEF_WIDGET;

   697 	w2->flags4 &= ~WF_WHITE_BORDER_MASK;

   698 

   699 	WP(w2, dropdown_d).disabled_state = disabled_mask;

   700 	WP(w2, dropdown_d).hidden_state = hidden_mask;

   701 

   702 	WP(w2, dropdown_d).parent_wnd_class = w->window_class;

   703 	WP(w2, dropdown_d).parent_wnd_num = w->window_number;

   704 	WP(w2, dropdown_d).parent_button = button;

   705 

   706 	WP(w2, dropdown_d).num_items = i;

   707 	WP(w2, dropdown_d).selected_index = selected;

   708 	WP(w2, dropdown_d).items = strings;

   709 

   710 	WP(w2, dropdown_d).click_delay = 0;

   711 	WP(w2, dropdown_d).drag_mode = true;

   712 }

   713