High DPI solution for the Delphi 7 applications which includes embed Chromium (DCEF)

[DimKas]

The Delphi7 applications can looks good in 4k monitors. The Windows 10 can help them. They're use 'DPI awareness' plus 'GDI scaling'. But if the application contains a component of the Chromium DCEF3 (or DCEF4 not matter), then collision occurs. Because to looks good the Chromium(DCEF) not need in 'GDI scaling' and 'DPI awareness'.

The simple way to switch the DPI apps by manifest file. For my app MShop.exe I've added the file MShop.exe.manifest:

Code: Select all

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
    <assemblyIdentity
        version="1.0.0.0"
        processorArchitecture="X86"
        name="Melbis Shop"
        type="win32"
    />
    <asmv3:application>
            <asmv3:windowsSettings>
                <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/pm</dpiAware> 
                <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2</dpiAwareness> 
                <gdiScaling xmlns="http://schemas.microsoft.com/SMI/2017/WindowsSettings">true</gdiScaling>
            </asmv3:windowsSettings>
        </asmv3:application>

    <description>Melbis Shop e-commerce</description>
    <dependency> 
        <dependentAssembly>
            <assemblyIdentity
                type="win32"
                name="Microsoft.Windows.Common-Controls"
                version="6.0.0.0"
                processorArchitecture="x86"
                publicKeyToken="6595b64144ccf1df"
                language="*"
            />
        </dependentAssembly>
    </dependency>
   <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
      <security>
      <requestedPrivileges>
        <requestedExecutionLevel
          level="requireAdministrator"
          uiAccess="false"/>
      </requestedPrivileges>
    </security>
   </trustInfo>
</assembly>

In this case I've good scaling for application (large icons and control's text), but with bad(not need) scaling for HTML-editor (DCEF3 component's):

scr1-1.png

If I use another way to NO to 'DPI awareness' in the file MShop.exe.manifest (only changed lines):

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<dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware> 
<dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">system</dpiAwareness> 

In this case I've no(bad) scaling for application (small icons and control's text), but with no(good) scaling for HTML-editor (DCEF3 component's):

scr2-1.png

May be, a possible way is to add the second manifest file for the Chromium component which placed in file libcef.dll?

[salvadordf]

Hi,

If you use a browser in normal mode then you can try adding this before the GlobalCEFApp.StartMainProcess call in the DPR file :

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GlobalCEFApp.AddCustomCommandLine('--force-device-scale-factor', '1');

The scale factor is calculated using this formula : scale = screen_DPI / 96
Try using different values instead of 1, for example 1.5 for a screen with a 150% scale.

If you use a browser in OSR mode then you can simulate any screen scale. See the WebpageSnapshot demo to know how to set a custom screen scale :
https://github.com/salvadordf/CEF4Delph ... ad.pas#L55

[salvadordf]

I just edited the previous message with the right switch --force-device-scale-factor

I'll upload a new CEF4Delphi version with a new GlobalCEFApp property to handle this more easily.

[salvadordf]

Please download CEF4Delphi from GitHub again and try the new GlobalCEFApp.ForcedDeviceScaleFactor property.