TCustomEdit right align makes caret position weird - delphi

I made a number edit (inherited from TCustomEdit) with fixed right alignment:
procedure TNumberEdit.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams(Params);
Params.Style := Params.Style or ES_RIGHT;
end;
Works, but the caret posotion looks weird, hiding part of the rightmost character:
Tried to set the the right margin with the following code:
Perform(EM_SETMARGINS, EC_RIGHTMARGIN, MakeLong(0, xWidth));
The margin appears, but doesnt make any difference bot the characters and the caret will get the offset.
How can I prevent this?
(Im using Delphi 7)

Related

Form opens in a random position in Delphi

I wanted to make that form would open in a random position on a screen.
I found the similar question here https://stackoverflow.com/a/51314375/19160533
But i didnt get how to implement this.
Im using Delphi 11.
Thanks!
You can set the top and left of the form on FormShow:
procedure TForm1.FormShow(Sender: TObject);
begin
self.Top := Random(1000);
left := Random(2000);
end;
for a better result, you can calculate the desktop dimensions and subtract the form width and height.

TDBGrid right align columns and set caret pos when editing value

I want to set the caret position in my derived TInplaceEdit in a derived DBGrid, similiar to a TDBGrid for right aligned columns.
procedure TMyGridEditor.CreateParams(var Params: TCreateParams);
const
Alignments : array[TAlignment] of LongWord= (ES_Left, ES_Right, ES_Center);
begin
inherited CreateParams(Params);
Params.Style := Params.Style or Alignments[FAlignment];
end;
procedure TMyGridEditor.UpdateContents;
begin
inherited;
// if Assigned(Grid) and Assigned(Grid.SelectedColumn) then begin
// Alignment := Grid.SelectedColumn.Alignment;
if (TDBGrid(Grid).SelectedIndex <> -1) then
Alignment := TDBGrid(Grid).Columns[TDBGrid(Grid).SelectedIndex].Alignment;
end;
Additional description:
Grid.SelectedColumn = Currently selected column of the grid
Sample picure: Column too small for value
Problem1: The caret position is always on the right and positioned after the last character, this looks strange for ie. string and memo contents. How can I set the caret to the left, just after the inplaceeditor will be displayed.
Problem2: The contents for number values are displayed on multiple lines, when there is not sufficient space avaiable (column is too small). This looks very strange.
How can I accomplish these tasks? Any help appreciated... Thanks

Is there a way to turn off the Caption on a TDBRadioGroup

I have a TDBRadioGroup that I've added to my form.
I'd really like to have the caption to the left of it instead of on top (the form's a little busy and tall, and I'm trying to squeeze it in).
I can add my own label to the left of the Radio Group. But the control insists on reserving space of a Caption that does not exists. Is there a way I can turn it off completely?
The best we've come up with so far is sticking it on a TPanel and then hiding the top couple lines off-panel.
A TGroupBox (and it's descendant TDBGroupBox) are basically wrappers around the Windows GroupBox. The control is designed to sport a user-defined label across the upper-left corner, and doesn't have any style setting to remove it.
So, short of creating your own control to host a series of TRadioButton controls yourself and display them, there's no built-in way to disable the space reserved for the caption. You can suppress the text, of course, by setting the Caption := '', but the padding for the text descenders is not removed simply because the caption isn't displayed.
You can override the paint procedure for TRadioGroup so that the frame is drawn closer to the top of your item list. You could create a new component of type TNoCaptionRadioGroup. You might still have to use the panel trick that you have tried, but by lowering the top of the frame you can grab the space consumed by the non-existent caption. Something like this:
tNoCaptionRadioBox = class(TRadioGroup)
protected
procedure paint; override;
end;
procedure tNoCaptionRadioBox.paint;
var
H: Integer;
R: TRect;
begin
with Canvas do
begin
Font := Self.Font;
H := TextHeight('0');
R := Rect(0, H, Width, Height);
if Ctl3D then
begin
Inc(R.Left);
Inc(R.Top);
Brush.Color := clBtnHighlight;
FrameRect(R);
OffsetRect(R, -1, -1);
Brush.Color := clBtnShadow;
end else
Brush.Color := clWindowFrame;
FrameRect(R);
end;
end;
This is taken from the code for painting a TCustomGroupBox. I have removed the code for drawing the caption and have changed the top of the frame to the full height of the Font. Your actual captioned radio buttons will still be drawn where Windows wants them to be and with the default spacing.
Remember to register the new component by running the package installation tool.
procedure Register;
begin
RegisterComponents('myComponents', [tNoCaptionRadioBox]);
end;

How to adjust a TrackBar thumb size?

I can't adjust a TTrackBar thumb size to a higher size. See the image:
I got a small thumb on the left, and I can't make it bigger (but not the TrackBar itself).
Desired thumb size is shown on an image with a red area.
Maybe I can use WINAPI somehow?
C++ apps have bigger thumb often.
This is what I'm actually hopping for:
It would seem like this cannot be done with the standard trackbar control. Indeed, I cannot see any trackbar style or trackbar message related to this. There is only the TBM_SETTHUMBLENGTH, which you also can access from VCL's TTrackBar.ThumbLength, but this also affects the height of the background sunken rectangle.
A corollory is that I doubt the observation that "C++ apps have bigger thumb often".
Of course, you can always make your own trackbar-like control.
Or do you only want to shrink the sunken rectangle? Then just set ShowSelRange to False in the Object Inspector. But if themes are on, you still cannot make the thumb bigger than about 24.
If you are on an old version of Delphi with no TrackBar.ShowSelRange, you need to remove the window style TBS_ENABLESELRANGE manually. You can do this at any time using SetWindowLong, or you can do it in CreateParams of a subclassed trackbar control. The simplest way might be to use an 'interposer class':
type
TTrackBar = class(ComCtrls.TTrackBar)
protected
procedure CreateParams(var Params: TCreateParams); override;
end;
...
implementation
{ TTrackBar }
procedure TTrackBar.CreateParams(var Params: TCreateParams);
begin
inherited;
Params.Style := Params.Style and not TBS_ENABLESELRANGE;
end;
To get the appearance in the Notepad++ screenshot, you should also set TickMarks to tmBoth and TickStyle to tsNone.
This doesn't answer your question, though, which was about making the thumb larger. This will make the sunken rectangle smaller... From your screenshots, however, I would guess this is what you want.
Trackbar is one of the native controls that support custom draw. Basically, when themes are enabled, you can control various aspects of drawing the control, or you can tell the OS that you're overtaking drawing parts yourself. See more about custom draw here.
We don't have to overtake any drawing to play with the sizes of some parts a little bit. It is the VCL that draws the channel (the recessed tracking background), and the ticks. For ticks, there are already properties we can use. For the channel, we can deflate the rectangle a bit, and the VCL will take over from there. The thumb is drawn by the default window procedure, but it doesn't matter, the OS will draw the thumb to the modified rectangle.
The below example (for a horizontal trackbar) intercepts WM_NOTIFY notification sent to the form to carry out these modifications. This will only work if the trackbar is placed directly on the form. If this is not the case, you can derive a new control that descends from TTrackBar to handle CN_NOTIFY, or subclass the control, or its parent for WM_NOTIFY. All that matters is to handle the notification before the actual drawing is performed.
This is how the example looks:
type
TForm1 = class(TForm)
Button1: TButton;
TrackBar1: TTrackBar;
procedure FormCreate(Sender: TObject);
protected
procedure WMNotify(var Msg: TWMNotify); message WM_NOTIFY;
end;
...
uses
themes, commctrl, xpman;
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
if ThemeServices.ThemesEnabled and
(TrackBar1.Orientation = trHorizontal) then begin
TrackBar1.TickMarks := tmBoth;
TrackBar1.TickStyle := tsNone;
TrackBar1.ThumbLength := 38;
end;
end;
procedure TForm1.WMNotify(var Msg: TWMNotify);
begin
if ThemeServices.ThemesEnabled and
(TrackBar1.Orientation = trHorizontal) then begin
if (Msg.IDCtrl = Longint(TrackBar1.Handle)) and
(Msg.NMHdr.code = NM_CUSTOMDRAW) and
(PNMCustomDraw(Msg.NMHdr).dwDrawStage = CDDS_ITEMPREPAINT) then begin
case PNMCustomDraw(Msg.NMHdr).dwItemSpec of
TBCD_THUMB: InflateRect(PNMCustomDraw(Msg.NMHdr).rc, -4, 0);
TBCD_CHANNEL:
with PNMCustomDraw(Msg.NMHdr).rc do begin
Top := Bottom div 2 + 2;
Bottom := Top + 5;
Inc(Left, 4);
Dec(Right, 4);
end;
end;
end;
end;
inherited;
end;

Problem with adding graphics to TLabel

I'm trying to create with Delphi a component inherited from TLabel, with some custom graphics added to it on TLabel.Paint. I want the graphics to be on left side of text, so I overrode GetClientRect:
function TMyComponent.GetClientRect: TRect;
begin
result := inherited GetClientRect;
result.Left := 20;
end;
This solution has major problem I'd like to solve: It's not possible to click on the "graphics area" of the control, only label area. If the caption is empty string, it's not possible to select the component in designer by clicking it at all. Any ideas?
First excuse-me for my bad English.
I think it is not a good idea change the ClientRect of the component. This property is used for many internal methods and procedures so you can accidentally change the functionality/operation of that component.
I think that you can change the point to write the text (20 pixels in the DoDrawText procedure -for example-) and the component can respond on events in the graphic area.
procedure TGrlabel.DoDrawText(var Rect: TRect; Flags: Integer);
begin
Rect.Left := 20;
inherited;
end;
procedure TGrlabel.Paint;
begin
inherited;
Canvas.Brush.Color := clRed;
Canvas.Pen.Color := clRed;
Canvas.pen.Width := 3;
Canvas.MoveTo(5,5);
Canvas.LineTo(15,8);
end;
What methods/functionality are you getting from TLabel that you need this component to do?
Would you perhaps be better making a descendent of (say, TImage) and draw your text as part of it's paint method?
If it's really got to be a TLabel descendant (with all that this entails) then I think you'll be stuck with this design-time issue, as doesn't TLabel have this problem anyway when the caption is empty?
I'll be interested in the other answers you get! :-)

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