Moving controls into view when the virtual keyboard is shown

Hello,
thanks for your sample app for scrolling the focused control element.
Unfortunately, it does not work correctly when the device is rotated.
Then the footer disappears and the memo component is moved to far up.
Maybe you have an idea how to fix this?
Bye,
Jürgen

Nice example. But how can I write a method to move the control when having a date time picker or a custom picker? Your class should handle those controls too (in IOS).

Some tweaks for Android, it can also now be registered as component and dropped onto a form. It will then automatically assign the form.

If the form already has any keyboard Shown or Hidden events assigned these are remembered and still triggered.

Still think GetViewRect for Android could be improved.

unit ControlMover;

interface

uses
FMX.Forms, FMX.Controls, System.Types, FMX.Types, System.Classes;

type
TSaveProperties = record
Control: TControl;
Align: TAlignLayout;
Position: TPointF;
end;

TGetMoveControlEvent = procedure(Sender: TObject; FocusedControl: TControl;
var MoveControl: TControl) of object;

TControlMover = class(TControl)
private
FForm: TCommonCustomForm;
FSaveProps: TSaveProperties;
FVKBounds: TRectF;
FVKVisible: Boolean;
FOnGetMoveControl: TGetMoveControlEvent;
FFormVirtualKeyboardShownEvent: TVirtualKeyboardEvent;
FFormVirtualKeyboardHiddenEvent: TVirtualKeyboardEvent;
procedure DoGetMoveControl;
function GetFocusedControlOffset(KeyboardRect: TRectF): Single;
function GetStatusBarHeight: Single;
function GetViewRect: TRectF;
function FocusedControl: TControl;
procedure FormVirtualKeyboardHidden(Sender: TObject;
KeyboardVisible: Boolean; const Bounds: TRect);
procedure FormVirtualKeyboardShown(Sender: TObject;
KeyboardVisible: Boolean; const Bounds: TRect);
function GetScreenOrientation: TScreenOrientation;
function VirtualKeyboardRectToAbsoluteRect(const Rect: TRectF;
const Scene: IScene): TRectF;
protected
procedure SetForm(AForm: TCommonCustomForm);
public
constructor Create(AOwner: TComponent); override;
procedure SlideControl;
published
property Form: TCommonCustomForm read FForm;
property OnGetMoveControl: TGetMoveControlEvent read FOnGetMoveControl
write FOnGetMoveControl;
end;

procedure Register;

implementation

uses
{$IFDEF MSWINDOWS}
ShellApi, Winapi.Windows, FMX.Forms,
{$ENDIF}
{$IFDEF ANDROID}
FMX.Platform.Android,
{$ENDIF}
{$IFDEF IOS}
iOSapi.UIKit, iOSapi.Foundation, FMX.Platform.iOS,
{$ENDIF}
FMX.Platform, System.Math, FMX.Memo;
{ TControlMover }

function TControlMover.GetScreenOrientation: TScreenOrientation;
var
{$IFDEF IOS}
App: UIApplication;
{$ELSE}
ScreenService: IFMXScreenService;
{$ENDIF}
begin
{$IFDEF IOS}
App := TUIApplication.Wrap(TUIApplication.OCClass.sharedApplication);

case App.statusBarOrientation of
UIInterfaceOrientationPortrait:
Result := TScreenOrientation.soPortrait;
UIInterfaceOrientationPortraitUpsideDown:
Result := TScreenOrientation.soInvertedPortrait;
UIInterfaceOrientationLandscapeLeft:
Result := TScreenOrientation.soLandscape;
UIInterfaceOrientationLandscapeRight:
Result := TScreenOrientation.soInvertedLandscape;

else
{$IFDEF DEBUG}
raise Exception.Create(‘Screen Orientation unknown’);
{$ELSE}
Result := TScreenOrientation.soPortrait;
{$ENDIF}
end;
{$ELSE}
if TPlatformServices.Current.SupportsPlatformService(IFMXScreenService,
IInterface(ScreenService)) then
Result := ScreenService.GetScreenOrientation()
else
Result := TScreenOrientation.soPortrait;
{$ENDIF}
end;

function TControlMover.VirtualKeyboardRectToAbsoluteRect
(const Rect: TRectF; const Scene: IScene): TRectF;
{$IFDEF IOS}
var
ScreenService: IFMXScreenService;
KeybdHeight: Single;
RealActualOrientation: TScreenOrientation;
UIApp: UIApplication;

function GetRealHeightOfTheKeyboard(const R: TRectF): Single;
var
ScreenSize: TPointF;
CertainlyFound: Boolean;
begin
ScreenSize := ScreenService.GetScreenSize();
CertainlyFound := False;
Result := 0;

if RealActualOrientation in [TScreenOrientation.soPortrait,
TScreenOrientation.soInvertedPortrait] then
begin
if ScreenSize.Y = R.Height then
begin
Result := R.Width;
CertainlyFound := True;
end
else if ScreenSize.Y = R.Width then
begin
Result := R.Height;
CertainlyFound := True;
end;
end
else
begin
if ScreenSize.X = R.Height then
begin
Result := R.Width;
CertainlyFound := True;
end
else if ScreenSize.X = R.Width then
begin
Result := R.Height;
CertainlyFound := True;
end;
end;

if not CertainlyFound then
Result := Min(R.Height, R.Width);
end;
{$ENDIF}

begin
{$IFDEF IOS}
Result := Rect;
RealActualOrientation := GetScreenOrientation();

if TPlatformServices.Current.SupportsPlatformService(IFMXScreenService,
IInterface(ScreenService)) then
begin
// Bug no iOS? Quando o dispositivo está em landscape, ele não informa a
// posição vertical do teclado virtual corretamente;
KeybdHeight := GetRealHeightOfTheKeyboard(Result);

if RealActualOrientation in [TScreenOrientation.soPortrait,
TScreenOrientation.soInvertedPortrait] then
Result.Bottom := ScreenService.GetScreenSize.Y
else
Result.Bottom := ScreenService.GetScreenSize.X;

Result.Top := Result.Bottom – KeybdHeight;
end;

UIApp := TUIApplication.Wrap(TUIApplication.OCClass.sharedApplication);

if RealActualOrientation in [TScreenOrientation.soLandscape,
TScreenOrientation.soInvertedLandscape] then
Result.Offset(0, -UIApp.statusBarFrame.size.Width)
else
Result.Offset(0, -UIApp.statusBarFrame.size.Height);

{$ELSE}
Result.TopLeft := Scene.ScreenToLocal(Rect.TopLeft);
Result.BottomRight := Scene.ScreenToLocal(Rect.BottomRight);
{$ENDIF}
end;

constructor TControlMover.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FFormVirtualKeyboardShownEvent := nil;
FFormVirtualKeyboardHiddenEvent := nil;
if (AOwner is TCommonCustomForm) then
begin
SetForm((AOwner as TCommonCustomForm));
end;
end;

procedure TControlMover.SetForm(AForm: TCommonCustomForm);
begin
if Assigned(FForm) then
begin
FForm.OnVirtualKeyboardShown := FFormVirtualKeyboardShownEvent;
FForm.OnVirtualKeyboardHidden := FFormVirtualKeyboardHiddenEvent;
end;

if Assigned(AForm) then
begin
FForm := AForm;
FFormVirtualKeyboardShownEvent := FForm.OnVirtualKeyboardShown;
FFormVirtualKeyboardHiddenEvent := FForm.OnVirtualKeyboardHidden;
FForm.OnVirtualKeyboardShown := FormVirtualKeyboardShown;
FForm.OnVirtualKeyboardHidden := FormVirtualKeyboardHidden;
end
else
begin
FForm := nil;
end;
end;

procedure TControlMover.FormVirtualKeyboardHidden(Sender: TObject;
KeyboardVisible: Boolean; const Bounds: TRect);
begin
FVKVisible := False;
if Assigned(FSaveProps.Control) then
begin
FSaveProps.Control.AnimateFloat(‘Position.Y’, FSaveProps.Position.Y, 0.1);
FSaveProps.Control.Align := FSaveProps.Align;
end;
if Assigned(FFormVirtualKeyboardHiddenEvent) then
begin
FFormVirtualKeyboardHiddenEvent(Sender, KeyboardVisible, Bounds);
end;
end;

procedure TControlMover.FormVirtualKeyboardShown(Sender: TObject;
KeyboardVisible: Boolean; const Bounds: TRect);
begin
FVKVisible := True;
FVKBounds := VirtualKeyboardRectToAbsoluteRect(TRectF.Create(Bounds),
TForm(FForm));
if FocusedControl = nil then
Exit;
DoGetMoveControl;
if Assigned(FSaveProps.Control) then
begin
FSaveProps.Align := FSaveProps.Control.Align;
FSaveProps.Control.Align := TAlignLayout.None;
FSaveProps.Position.Y := FSaveProps.Control.Position.Y;
SlideControl;
end;
if Assigned(FFormVirtualKeyboardShownEvent) then
begin
FFormVirtualKeyboardShownEvent(Sender, KeyboardVisible, Bounds);
end;
end;

procedure TControlMover.DoGetMoveControl;
var
MoveControl: TControl;
begin
MoveControl := nil;
if Assigned(FOnGetMoveControl) then
FOnGetMoveControl(Self, FocusedControl, MoveControl);
FSaveProps.Control := MoveControl;
end;

function TControlMover.FocusedControl: TControl;
begin
Result := nil;
if Assigned(FForm.Focused) and (FForm.Focused.GetObject is TControl) then
Result := TControl(FForm.Focused.GetObject);
end;

function TControlMover.GetFocusedControlOffset
(KeyboardRect: TRectF): Single;
var
Control: TControl;
ControlPos: TPointF;
ControlHeight: Single;
Memo: TMemo;
Caret: TCaret;
ViewRect: TRectF;
begin
Result := 0;
Control := FocusedControl;
if Assigned(Control) then
begin
ControlPos := Control.LocalToAbsolute(PointF(0, 0));
ControlHeight := Control.Height;
if Control is TMemo then
begin
Memo := TMemo(Control);
Caret := Memo.Caret;
ControlPos.Y := ControlPos.Y + (Caret.Pos.Y – Memo.ViewportPosition.Y);
ControlHeight := Caret.size.Height + 4;
end;
ViewRect := GetViewRect;
Result := (ControlPos.Y + ControlHeight + 2)
// Subtract the keyboard height from the view height to obtain the actual top of the keyboard
– ((ViewRect.Bottom – ViewRect.Top) – (KeyboardRect.Bottom –
KeyboardRect.Top))
// Add the status bar height
+ GetStatusBarHeight;
if Result < 0 then
Result := 0;
end;
end;

function TControlMover.GetStatusBarHeight: Single;
{$IFDEF IOS}
begin
Result := 30; // modified by Patrick 14/02/2014
{$IFDEF CPUARM} // i.e. on an iOS device
// if TOSVersion.Check(7, 0) then
// Result := TUIApplication.wrap(TUIApplication.OCClass.SharedApplication).statusBarFrame.size.height; // commented by Patrick 14/02/2014
{$ENDIF}
end;
{$ELSE}

begin
Result := 0;
end;
{$ENDIF}

function TControlMover.GetViewRect: TRectF;
{$IFDEF IOS}
var
ARect: NSRect;
begin
ARect := WindowHandleToPlatform(FForm.Handle).View.Bounds;
Result := RectF(ARect.origin.X, ARect.origin.Y,
ARect.size.Width – ARect.origin.X, ARect.size.Height – ARect.origin.Y);
end;
{$ELSE}
{$IFDEF ANDROID}

begin
Result := WindowHandleToPlatform(FForm.Handle).Bounds;
end;
{$ELSE}

begin
// Nothing
end;
{$ENDIF ANDROID}
{$ENDIF IOS}

procedure TControlMover.SlideControl;
begin
if FVKVisible and Assigned(FSaveProps.Control) then
FSaveProps.Control.AnimateFloat('Position.Y', FSaveProps.Control.Position.Y
– GetFocusedControlOffset(FVKBounds), 0.1);
end;

procedure Register;
begin
RegisterComponents('Form Helpers', [TControlMover]);
end;

end.