Make dialogs compatible with "large fonts".<>
This question already has an answer here:
There's a pretty good article in the D2007 help file, under "Considerations When Dynamically Resizing Forms and Controls" (note that the URL is to the help file itself, and not a web page as such).
It also is worthwhile (at least a little bit) to examine TForm.Scaled and TForm.ScaleBy.
In general one should use layout managers for this purpose. That what they are designed for.
Delphi (did not work with it for a long time) does not have such managers but is able to handle different dpi ever since. You have to use the autosize propery of the components to ensure that they have the right size for the text they display. To prevent overlapping of components arrange them on the form using the alignment and anchor properties. Eventually you have to group components in containers to achieve a proper layout.
This is how I try to deal with Delphi VCL's pixels regardless of Window's font size setting.
unit App.Screen; interface uses Controls; type TAppScreen = class(TObject) private FDefaultPixelsPerInch: integer; FPixelsPerInch: integer; function GetPixelsPerInch: integer; procedure SetPixelsPerInch(const Value: integer); public procedure AfterConstruction; override; function DefaultPixelsPerInch: integer; function InAcceptableRange(const aPPI: integer): boolean; procedure ScaleControl(const aControl: TWinControl); property PixelsPerInch: integer read GetPixelsPerInch write SetPixelsPerInch; end; TAppScreenHelper = class helper for TAppScreen private class var FInstance: TAppScreen; class function GetInstance: TAppScreen; static; public class procedure Setup; class procedure TearDown; class property Instance: TAppScreen read GetInstance; end; implementation uses TypInfo, Windows, SysUtils, Forms, Graphics; type TScreenEx = class(TScreen) published property PixelsPerInch; end; TScreenHelper = class helper for TScreen public procedure SetPixelsPerInch(Value: integer); end; procedure TScreenHelper.SetPixelsPerInch(Value: integer); begin PInteger(Integer(Self) + (Integer(GetPropInfo(TScreenEx, 'PixelsPerInch').GetProc) and $00FFFFFF))^ := Value; end; procedure TAppScreen.AfterConstruction; begin inherited; FDefaultPixelsPerInch := Screen.PixelsPerInch; FPixelsPerInch := FDefaultPixelsPerInch; end; function TAppScreen.DefaultPixelsPerInch: integer; begin Result := FDefaultPixelsPerInch; end; function TAppScreen.GetPixelsPerInch: integer; begin Result := FPixelsPerInch; end; function TAppScreen.InAcceptableRange(const aPPI: integer): boolean; begin if DefaultPixelsPerInch > aPPI then Result := DefaultPixelsPerInch * 0.55 < aPPI else if DefaultPixelsPerInch < aPPI then Result := DefaultPixelsPerInch * 1.55 > aPPI else Result := True; end; procedure TAppScreen.ScaleControl(const aControl: TWinControl); begin aControl.ScaleBy(PixelsPerInch, DefaultPixelsPerInch); end; procedure TAppScreen.SetPixelsPerInch(const Value: integer); begin FPixelsPerInch := Value; Screen.SetPixelsPerInch(FPixelsPerInch); end; class function TAppScreenHelper.GetInstance: TAppScreen; begin if FInstance = nil then FInstance := TAppScreen.Create; Result := FInstance; end; class procedure TAppScreenHelper.Setup; begin TAppScreen.Instance; end; class procedure TAppScreenHelper.TearDown; begin FInstance.Free; FInstance := nil; end; initialization TAppScreen.Setup; finalization TAppScreen.TearDown; end.
Try the following to test the effects of different pixels value:
TAppScreen.Instance.PixelsPerInch := 120; TAppScreen.Instance.PixelsPerInch := 96; TAppScreen.Instance.PixelsPerInch := 150;
You should change the PixelsPerInch before instantiate TForm's descendant including Delphi's VCL dialogs.
- Never put a control and its describing label side by side, always put the label on top of it.
But apart from that? Maybe:
- Leave enough space to the right and bottom of labels so they will not overlap with other controls when large fonts are used.
I have never tried using TLabeledEdit in that scenario, maybe they do that automatically?
There are purported commercial solutions (Developer Express VCL Layout Manager). But I do not trust any of them. I suspect that Embarcadero should address this as a critical weakness in the current UI component set (VCL).
I think that the third-party component set might be your fastest solution right now. It's commercial but not hugely expensive.