src/vs/base/parts/quickinput/browser/quickInput.ts/QuickPick/show
class QuickPick:	override show() {
		if (!this.visible) {
			this.visibleDisposables.add(
				this.ui.inputBox.onDidChange(value => {
					if (value === this.value) {
						return;
					}
					this._value = value;
					const didFilter = this.ui.list.filter(this.filterValue(this.ui.inputBox.value));
					if (didFilter) {
						this.trySelectFirst();
					}
					this.onDidChangeValueEmitter.fire(value);
				}));
			this.visibleDisposables.add(this.ui.inputBox.onMouseDown(event => {
				if (!this.autoFocusOnList) {
					this.ui.list.clearFocus();
				}
			}));
			this.visibleDisposables.add((this._hideInput ? this.ui.list : this.ui.inputBox).onKeyDown((event: KeyboardEvent | StandardKeyboardEvent) => {
				switch (event.keyCode) {
					case KeyCode.DownArrow:
						this.ui.list.focus(QuickInputListFocus.Next);
						if (this.canSelectMany) {
							this.ui.list.domFocus();
						}
						dom.EventHelper.stop(event, true);
						break;
					case KeyCode.UpArrow:
						if (this.ui.list.getFocusedElements().length) {
							this.ui.list.focus(QuickInputListFocus.Previous);
						} else {
							this.ui.list.focus(QuickInputListFocus.Last);
						}
						if (this.canSelectMany) {
							this.ui.list.domFocus();
						}
						dom.EventHelper.stop(event, true);
						break;
					case KeyCode.PageDown:
						this.ui.list.focus(QuickInputListFocus.NextPage);
						if (this.canSelectMany) {
							this.ui.list.domFocus();
						}
						dom.EventHelper.stop(event, true);
						break;
					case KeyCode.PageUp:
						this.ui.list.focus(QuickInputListFocus.PreviousPage);
						if (this.canSelectMany) {
							this.ui.list.domFocus();
						}
						dom.EventHelper.stop(event, true);
						break;
					case KeyCode.RightArrow:
						if (!this._canAcceptInBackground) {
							return; // needs to be enabled
						}

						if (!this.ui.inputBox.isSelectionAtEnd()) {
							return; // ensure input box selection at end
						}

						if (this.activeItems[0]) {
							this._selectedItems = [this.activeItems[0]];
							this.onDidChangeSelectionEmitter.fire(this.selectedItems);
							this.handleAccept(true);
						}

						break;
					case KeyCode.Home:
						if ((event.ctrlKey || event.metaKey) && !event.shiftKey && !event.altKey) {
							this.ui.list.focus(QuickInputListFocus.First);
							dom.EventHelper.stop(event, true);
						}
						break;
					case KeyCode.End:
						if ((event.ctrlKey || event.metaKey) && !event.shiftKey && !event.altKey) {
							this.ui.list.focus(QuickInputListFocus.Last);
							dom.EventHelper.stop(event, true);
						}
						break;
				}
			}));
			this.visibleDisposables.add(this.ui.onDidAccept(() => {
				if (!this.canSelectMany && this.activeItems[0]) {
					this._selectedItems = [this.activeItems[0]];
					this.onDidChangeSelectionEmitter.fire(this.selectedItems);
				}
				this.handleAccept(false);
			}));
			this.visibleDisposables.add(this.ui.onDidCustom(() => {
				this.onDidCustomEmitter.fire();
			}));
			this.visibleDisposables.add(this.ui.list.onDidChangeFocus(focusedItems => {
				if (this.activeItemsUpdated) {
					return; // Expect another event.
				}
				if (this.activeItemsToConfirm !== this._activeItems && equals(focusedItems, this._activeItems, (a, b) => a === b)) {
					return;
				}
				this._activeItems = focusedItems as T[];
				this.onDidChangeActiveEmitter.fire(focusedItems as T[]);
			}));
			this.visibleDisposables.add(this.ui.list.onDidChangeSelection(({ items: selectedItems, event }) => {
				if (this.canSelectMany) {
					if (selectedItems.length) {
						this.ui.list.setSelectedElements([]);
					}
					return;
				}
				if (this.selectedItemsToConfirm !== this._selectedItems && equals(selectedItems, this._selectedItems, (a, b) => a === b)) {
					return;
				}
				this._selectedItems = selectedItems as T[];
				this.onDidChangeSelectionEmitter.fire(selectedItems as T[]);
				if (selectedItems.length) {
					this.handleAccept(event instanceof MouseEvent && event.button === 1 /* mouse middle click */);
				}
			}));
			this.visibleDisposables.add(this.ui.list.onChangedCheckedElements(checkedItems => {
				if (!this.canSelectMany) {
					return;
				}
				if (this.selectedItemsToConfirm !== this._selectedItems && equals(checkedItems, this._selectedItems, (a, b) => a === b)) {
					return;
				}
				this._selectedItems = checkedItems as T[];
				this.onDidChangeSelectionEmitter.fire(checkedItems as T[]);
			}));
			this.visibleDisposables.add(this.ui.list.onButtonTriggered(event => this.onDidTriggerItemButtonEmitter.fire(event as IQuickPickItemButtonEvent<T>)));
			this.visibleDisposables.add(this.registerQuickNavigation());
			this.valueSelectionUpdated = true;
		}
		super.show(); // TODO: Why have show() bubble up while update() trickles down? (Could move setComboboxAccessibility() here.)
	}