How to create "No Activate" form in Firemonkey

Question

In XCode by adding these methods to your NSView subclass can prevent the window from becoming active when clicking on it:

- (BOOL)shouldDelayWindowOrderingForEvent:(NSEvent )theEvent {
    return YES;
}
- (BOOL)acceptsFirstMouse:(NSEvent )theEvent {
    return YES; 
}
- (void)mouseDown:(NSEvent )theEvent {
    [[[NSApp]] preventWindowOrdering]; 
}

In Windows platform It is done by this simple code:

HWND hWnd = FindWindowW((String("FM") + fmxForm->ClassName()).c_str(), 
    fmxForm->Caption.c_str());

SetWindowLong(hWnd, GWL_EXSTYLE,
    GetWindowLong(hWnd, GWL_EXSTYLE) | WS_EX_NOACTIVATE);

How can I subclass NSView to prevent my FMX TForm becoming active when clicking on it?

How can I create "No Activate" form in firemonkey?

Answer 1

It is possible using NSPanel with NSNonactivatingPanelMask flag. The NSView of fmx form should become child of NSPanel. I have written a helper class which works for both Windows and Mac platforms (Works on XE4):

unit NoActivateForm;

interface

uses Fmx.Forms, Fmx.Types
{$IFDEF POSIX}
    , Macapi.AppKit
{$ENDIF}
    ;

type TNoActivateForm = class
private
    form: TForm;
{$IFDEF POSIX}
    panel: NSPanel;
    timer: TTimer;  // for simulating mouse hover event
{$ENDIF}
    procedure SetPosition(const x, y: Integer);
    procedure GetPosition(var x, y: Integer);
    procedure SetDimensions(const width, height: Integer);
    procedure SetLeft(const Value: Integer);
    procedure SetTop(const Value: Integer);
    procedure SetHeight(const Value: Integer);
    procedure SetWidth(const Value: Integer);
    procedure SetVisible(const Value: Boolean);
    function GetLeft: Integer;
    function GetTop: Integer;
    function GetHeight: Integer;
    function GetWidth: Integer;
    function GetVisible: Boolean;
{$IFDEF POSIX}
    procedure OnTimer(Sender: TObject);
{$ENDIF}
public
    constructor Create(AForm: TForm);
    destructor Destroy; override;
    property Left: Integer read GetLeft write SetLeft;
    property Top: Integer read GetTop write SetTop;
    property Height: Integer read GetHeight write SetHeight;
    property Width: Integer read GetWidth write SetWidth;
    property Visible: Boolean read GetVisible write SetVisible;
end;

implementation
uses
    Classes, System.Types
{$IFDEF MSWINDOWS}
    , Winapi.Windows;
{$ELSE}
    , Macapi.CocoaTypes, FMX.Platform.Mac, Macapi.CoreGraphics, Macapi.CoreFoundation;
{$ENDIF}

constructor TNoActivateForm.Create(AForm: TForm);
{$IFDEF POSIX}
var
    rect: NSRect;
    bounds: CGRect;
    window: NSWindow;
    style: integer;
    panelCount: integer;
begin
    form := AForm;
    form.Visible := false;
    bounds := CGDisplayBounds(CGMainDisplayID);
    rect := MakeNSRect(form.Left, bounds.size.height - form.Top - form.Height,
        form.ClientWidth, form.ClientHeight);
    style := NSNonactivatingPanelMask;
    style := style or NSHUDWindowMask;
    panel := TNSPanel.Wrap(
        TNSPanel.Alloc.initWithContentRect(rect, style, NSBackingStoreBuffered,
        true));
    panel.setFloatingPanel(true);
    //panel.setHasShadow(false); optional
    window := WindowHandleToPlatform(form.Handle).Wnd;

    panel.setContentView(TNSView.Wrap(window.contentView));
    TNSView.Wrap(window.contentView).retain;

    timer := TTimer.Create(form.Owner);
    timer.OnTimer := OnTimer;
    timer.Interval := 50;
end;
{$ELSE}
var hWin: HWND;
begin
    form := AForm;
    form.TopMost := true;
    hWin := FindWindow(PWideChar('FM' + form.ClassName), PWideChar(form.Caption));
    if hWin <> 0 then
        SetWindowLong(hWin, GWL_EXSTYLE,
            GetWindowLong(hWin, GWL_EXSTYLE) or WS_EX_NOACTIVATE);
end;
{$ENDIF}

destructor TNoActivateForm.Destroy;
{$IFDEF POSIX}
begin
    panel.release;
end;
{$ELSE}
begin
end;
{$ENDIF}

procedure TNoActivateForm.SetPosition(const x, y: Integer);
{$IFDEF POSIX}
var point: NSPoint;
    screen: CGRect;
begin
    screen := CGDisplayBounds(CGMainDisplayID);
    point.x := x;
    point.y := round(screen.size.height) - y - form.height;
    panel.setFrameOrigin(point);
end;
{$ELSE}
begin
    form.Left := x;
    form.Top := y;
end;
{$ENDIF}

procedure TNoActivateForm.GetPosition(var x, y: Integer);
{$IFDEF POSIX}
var screen: CGRect;
begin
    screen := CGDisplayBounds(CGMainDisplayID);
    x := round(panel.frame.origin.x);
    y := round(screen.size.height - panel.frame.origin.y - panel.frame.size.height);
end;
{$ELSE}
begin
    x := form.Left;
    y := form.Top;
end;
{$ENDIF}

procedure TNoActivateForm.SetDimensions(const width, height: Integer);
{$IFDEF POSIX}
var size: NSSize;
begin
    size.width := width;
    size.height := height;
    panel.setContentSize(size);
end;
{$ELSE}
begin
    form.width := width;
    form.height := height;
end;
{$ENDIF}

procedure TNoActivateForm.SetLeft(const Value: Integer);
begin
    SetPosition(Value, Top);
end;

procedure TNoActivateForm.SetTop(const Value: Integer);
begin
    SetPosition(Left, Value);
end;

procedure TNoActivateForm.SetHeight(const Value: Integer);
begin
    SetDimensions(Width, Value);
end;

procedure TNoActivateForm.SetWidth(const Value: Integer);
begin
    SetDimensions(Value, Height);
end;

procedure TNoActivateForm.SetVisible(const Value: Boolean);
begin
{$IFDEF POSIX}
    panel.setIsVisible(Value);
{$ELSE}
    form.visible := Value;
{$ENDIF}
end;

function TNoActivateForm.GetLeft: Integer;
var x, y: Integer;
begin
    GetPosition(x, y);
    result := x;
end;

function TNoActivateForm.GetTop: Integer;
var x, y: Integer;
begin
    GetPosition(x, y);
    result := y;
end;

function TNoActivateForm.GetHeight: Integer;
begin
{$IFDEF POSIX}
    result := round(panel.frame.size.height);
{$ELSE}
    result := form.Height;
{$ENDIF}
end;

function TNoActivateForm.GetWidth: Integer;
begin
{$IFDEF POSIX}
    result := round(panel.frame.size.width);
{$ELSE}
    result := form.Width;
{$ENDIF}
end;

function TNoActivateForm.GetVisible: Boolean;
begin
{$IFDEF POSIX}
    result := panel.isVisible();
{$ELSE}
    result := form.visible;
{$ENDIF}
end;

{$IFDEF POSIX}
procedure TNoActivateForm.OnTimer(Sender: TObject);
var event: CGEventRef;
    point: CGPoint;
    form_rect: TRectF;
    client_point, mouse_loc: TPointF;
    shift: TShiftState;
begin
    event := CGEventCreate(nil);
    point := CGEventGetLocation(event);
    CFRelease(event);
    mouse_loc.SetLocation(point.x, point.y);
    if Visible = true then
    begin
        form_rect := RectF(0, 0, form.Width, form.Height);
        client_point.X := mouse_loc.X - Left;
        client_point.Y := mouse_loc.y - Top;
        if PtInRect(form_rect, client_point) then
            form.MouseMove(shift, client_point.x, client_point.y)
        else
            form.MouseLeave();
    end;
end;
{$ENDIF}

end.

Usage of above unit:

TNoActivateForm *naKeyboard; // global scope    
void __fastcall TfrmKeyboard::TfrmKeyboard(TObject *Sender)
{
    naKeyboard = new TNoActivateForm(frmKeyboard); // frmKeyboard is a normal fmx form
    naKeyboard->Visible = true;
}

If frmKeyboard is your Main Form then do not put above code in form constructor, It is recommended to put it in OnShow.

Note: WindowHandleToPlatform doesn't seem to exist in XE3 so that line can be replaced with

window := NSWindow(NSWindowFromObjC(FmxHandleToObjC(Form.Handle)));