C++ ChildAt函數代碼示例

status_t
BDragger::_DetermineRelationship()
{
	if (fTarget) {
		if (fTarget == Parent())
			fRelation = TARGET_IS_PARENT;
		else if (fTarget == ChildAt(0))
			fRelation = TARGET_IS_CHILD;
		else
			fRelation = TARGET_IS_SIBLING;
	} else {
		if (fRelation == TARGET_IS_PARENT)
			fTarget = Parent();
		else if (fRelation == TARGET_IS_CHILD)
			fTarget = ChildAt(0);
		else
			return B_ERROR;
	}

	if (fRelation == TARGET_IS_PARENT) {
		BRect bounds (Frame());
		BRect parentBounds (Parent()->Bounds());
		if (!parentBounds.Contains(bounds))
			MoveTo(parentBounds.right - bounds.Width(),
				parentBounds.bottom - bounds.Height());
	}

	return B_OK;
}

void NavigatorEditor::DetachedFromWindow(void)
{
	TRACE();
	while (ChildAt(0)!=NULL)
	{
		RemoveChild(ChildAt(0));
	}
}

void TMediaTabView::MessageReceived(BMessage* message)
{
	// Check for messages to switch the view
	bool buttonMsg = false;
	EChildID newView;
	switch (message->what)
	{
	case MEDIA_TAB_LIST_VIEW_MSG:
		newView = kElementsView;
		buttonMsg = true;
		break;
	case MEDIA_TAB_THUMBNAIL_VIEW_MSG:
		newView = kThumbnailView;
		buttonMsg = true;
		break;
	case MEDIA_TAB_ICON_VIEW_MSG:
		newView = kIconView;
		buttonMsg = true;
		break;
	}
	if (buttonMsg) {
		if (newView != fCurrentView) {
			// Protect this section of code.
			Looper()->Lock();

			DeactivateView(fCurrentView);
			fCurrentView = newView;
			ActivateView(fCurrentView);

			Looper()->Unlock();
		}

		return;
	}

	// Accept messages from the sorter object
	switch (message->what)
	{
	case SORTER_SELECT_MSG:
	case SORTER_INVOKE_MSG:
		if (fCurrentView == kElementsView)
			ChildAt(fCurrentView)->MessageReceived(message);
		return;

	// Some cue is adding an entry_ref to our browser
	// TODO: include the other two views in this. They can
	// have a new REF as well.
	case ADD_REF_MSG:
		if (fCurrentView == kElementsView)
			ChildAt(fCurrentView)->MessageReceived(message);
		return;
	}

	// Default handler
	BView::MessageReceived(message);
}

SMTPConfigView::SMTPConfigView(MailAddonSettings& settings,
	BMailAccountSettings& accountSettings)
	:
	BMailProtocolConfigView(B_MAIL_PROTOCOL_HAS_AUTH_METHODS
		| B_MAIL_PROTOCOL_HAS_USERNAME | B_MAIL_PROTOCOL_HAS_PASSWORD
		| B_MAIL_PROTOCOL_HAS_HOSTNAME
#ifdef USE_SSL
		| B_MAIL_PROTOCOL_HAS_FLAVORS
#endif
		)
{
#if defined(USE_SSL) || defined(B_COLLECTING_CATKEYS)
	static const char* kUnencryptedStr = B_TRANSLATE_MARK("Unencrypted");
	static const char* kSSLStr = B_TRANSLATE_MARK("SSL");
	static const char* kSTARTTLSStr = B_TRANSLATE_MARK("STARTTLS");
#endif

#ifdef USE_SSL
	AddFlavor(B_TRANSLATE_NOCOLLECT(kUnencryptedStr));
	AddFlavor(B_TRANSLATE(kSSLStr));
	AddFlavor(B_TRANSLATE(kSTARTTLSStr));
#endif

	AddAuthMethod(B_TRANSLATE("None"), false);
	AddAuthMethod(B_TRANSLATE("ESMTP"));
	AddAuthMethod(B_TRANSLATE("POP3 before SMTP"), false);

	BTextControl *control = (BTextControl *)(FindView("host"));
	control->SetLabel(B_TRANSLATE("SMTP server:"));

	// Reset the dividers after changing one
	float widestLabel = 0;
	for (int32 i = CountChildren(); i-- > 0;) {
		if (BTextControl *text = dynamic_cast<BTextControl *>(ChildAt(i)))
			widestLabel = MAX(widestLabel,text->StringWidth(text->Label()) + 5);
	}
	for (int32 i = CountChildren(); i-- > 0;) {
		if (BTextControl *text = dynamic_cast<BTextControl *>(ChildAt(i)))
			text->SetDivider(widestLabel);
	}

	BMenuField *field = (BMenuField *)(FindView("auth_method"));
	field->SetDivider(widestLabel);

	SetTo(settings);

	fFileView = new BMailFileConfigView(B_TRANSLATE("Destination:"), "path",
		false, BPrivate::default_mail_out_directory().Path());
	fFileView->SetTo(&settings.Settings(), NULL);
	AddChild(fFileView);
	float w, h;
	BMailProtocolConfigView::GetPreferredSize(&w, &h);
	fFileView->MoveBy(0, h - 10);
	GetPreferredSize(&w, &h);
	ResizeTo(w, h);
}

void
ThemeInterfaceView::PopulateThemeList()
{
	int i;
	BControl *c;
	for (i = 0; ChildAt(i); i++) {
		c = dynamic_cast<BControl *>(ChildAt(i));
		if (c)
			c->SetEnabled(false);
	}
	thread_id tid = spawn_thread(_ThemeListPopulatorTh, "ThemeListPopulator", 
		B_LOW_PRIORITY, this);
	resume_thread(tid);
}

void CSettingsGroup::FrameResized(float width, float height)
{
	CBox::FrameResized(width, height);

	BRect clientRect = ClientRect();

	float ypos = clientRect.top+dist;
	float columnWidth = (clientRect.Width() - numColumns*dist - dist) / numColumns;
	
	for(int32 i=0 ; i<CountChildren() ; i++) {
		BView *child = ChildAt(i);
		
		float childWidth, childHeight;
		
		child->GetPreferredSize(&childWidth, &childHeight);
		
		int32 column = i%numColumns;
		
		child->MoveTo(clientRect.left+column*(columnWidth+dist)+dist, ypos);
		child->ResizeTo(columnWidth, childHeight);
		
		if(((i+1)%numColumns) == 0)
			ypos += childHeight+dist;
	}
}

void
PackagesView::FrameResized(float width, float height)
{
    if (CountChildren() == 0)
        Invalidate();

    BScrollBar* scrollBar = ScrollBar(B_VERTICAL);
    if (scrollBar == NULL)
        return;

    float virtualHeight = 0.0;

    int32 count = CountChildren();
    if (count > 0) {
        BView* child = ChildAt(count - 1);
        virtualHeight = child->Frame().bottom;
    }

    if (height > virtualHeight) {
        scrollBar->SetRange(0.0f, 0.0f);
        scrollBar->SetValue(0.0f);
    } else {
        scrollBar->SetRange(0.0f, virtualHeight - height);
        scrollBar->SetProportion(height / virtualHeight);
    }

    scrollBar->SetSteps(15, height);
}

void TMediaTabView::ActivateView(EChildID which)
{
	// Give the view the control buttons
	BView* view = ChildAt(which);

	BPoint pt = view->Bounds().LeftBottom();
	// Get the target button position. Slightly different for the
	// different view types.
	if (which == kElementsView)
		pt.y -= kScrollHeight;
	else {
		pt.x++;
		pt.y -= kScrollHeight + 1;
	}

	for (int i = 0; i < 3; i++) {
		view->AddChild(fbuttons[i]);
		fbuttons[i]->MoveTo(pt);
		pt.x += kScrollHeight;
	}

	// Make sure it is visible
	if (view->IsHidden())
		view->Show();
}

/*!	Since we have set a mouse event mask, we don't want to forward all
	mouse downs to the slider - instead, we only invoke it, which causes a
	message to our target. Within the VolumeWindow, this will actually
	cause the window to close.
	Also, we need to mask out the dragger in this case, or else dragging
	us will also cause a volume update.
*/
void
VolumeControl::MouseDown(BPoint where)
{
	// Ignore clicks on the dragger
	int32 viewToken;
	if (Bounds().Contains(where) && Looper()->CurrentMessage() != NULL
		&& Looper()->CurrentMessage()->FindInt32("_view_token",
				&viewToken) == B_OK
		&& viewToken != _get_object_token_(this))
		return;

	// TODO: investigate why this does not work as expected (the dragger
	// frame seems to be off)
#if 0
	if (BView* dragger = ChildAt(0)) {
		if (!dragger->IsHidden() && dragger->Frame().Contains(where))
			return;
	}
#endif

	if (!IsEnabled() || !Bounds().Contains(where)) {
		Invoke();
		return;
	}

	BSlider::MouseDown(where);
}

status_t
BBox::SetLabel(BView *viewLabel)
{
	if (viewLabel != NULL) {
		if (viewLabel == this || viewLabel->Window() != NULL || viewLabel->Parent() != NULL) return B_ERROR;
		AddChild(viewLabel, ChildAt(0));
		if (viewLabel->Parent() != this) return B_ERROR;
		viewLabel->SetResizingMode(B_FOLLOW_NONE);
	} else if (fLabelView == NULL) {
		return B_OK;
	}

	if (fLabelView != NULL) {
		BView *view = fLabelView;
		fLabelView = NULL;

		view->RemoveSelf();
		delete view;
	}

	fLabelView = viewLabel;
	ReAdjustLabel();

	return B_OK;
}

void CollapsableBox::SetValue(int32 new_value)
{
	if (new_value != Value()) {
		BRect r = Bounds();
		
		if (!new_value)
			ResizeTo(r.Width(), m_collapsed_rect.Height());
		else
			ResizeTo(r.Width(), m_expanded_rect.Height());
		
		BView *child;
		
		child = ChildAt(0);
		while (child) {
			if (new_value)
				child->Show();
			else
				child->Hide();
			child = child->NextSibling();
		};
			
		Invalidate();
		BControl::SetValue(new_value);
		Invoke();
	};
	
}

void MainView::DisplayRecord(Record *record, XFileMode mode) 
{
	Field * child = NULL;
	BString data;
	
	if ( (child = (Field *)ChildAt(0)) != NULL ) {
  		while ( child ) {
  			if(mode == DATA_MODE) {
	  			if(child->IsDataField()) {
	  				if(record->GetDataByFieldName(child->GetName(), data)) {
	  					printf("has data\n");
	  				}
	  				child->SetData(data);
	  			}	
  			}
	  		else if(mode == DESIGN_MODE)
	  		{
	  			data.SetTo(child->GetName());
	  			child->SetData(data);
	  		}
	  		child = (Field *) child->NextSibling();
  		}
  		
	}
}

void MainView::selectFieldByPoint(const BPoint& point)
{
	bool selected = false;
	Field * child = NULL;
	
	selected_fields.MakeEmpty();
	
	if ( (child = (Field *)ChildAt(0)) != NULL ) {
  		while ( child ) {
			if(selected == false && child->Frame().Contains(point)) {
				child->SetSelected(true);
				selected_fields.AddItem(child);
				selected = true;
			}
			else {
				child->SetSelected(false);
			}
			child->Invalidate();
			child = (Field *)child->NextSibling();
  		}
	}
	if(selected_fields.CountItems() > 0) {
		getSelBounds(sel_bounds);
	}
}

void
SetupWindow::MessageReceived(BMessage* msg)
{
	bool success;

	switch (msg->what) {
		case M_OK:
			Lock();
			success = ((SetupView*)ChildAt(0))->CheckSetup();
			Unlock();
			if (success) {
				fResult = B_NO_ERROR;
				release_sem(fExitSem);
			}
			break;

		case M_CANCEL:
			fResult = B_ERROR;
			release_sem(fExitSem);
			break;

		default:
			BWindow::MessageReceived(msg);
			break;
	}
}

// _FindIcon
IconButton*
IconOptionsControl::_FindIcon(int32 index) const
{
	if (BView* view = ChildAt(index))
		return dynamic_cast<IconButton*>(view);
	return NULL;
}