Letterboxing since 32220 affected by layout.css.devPixelsPerPx
This submission includes 3 sections: (1) Summary of Issue, (2) Detailed Description of Issue, and (3) Desired Outcome.
(1) Summary of Issue —
When using Tor Browser on a MacBook Air 13-inch laptop computer, the default configuration about:config > layout.css.devPixelsPerPx Value -1.0 (screenshot 1) renders too small the size of content in the Toolbar, the size of bookmarks folders and text in the Bookmarks Toolbar, and the size of content in the browser inner window. The small size leads to user eyestrain that is largely avoided when Tor Browser uses modified configuration about:config > layout.css.devPixelsPerPx Value 2.4 (screenshot 2).
Modified configuration about:config > layout.css.devPixelsPerPx Value 2.4 prevents user eyestrain when using Tor Browser on a MacBook Air 13-inch laptop, but, when Tor Browser 9.5.3 is using this configuration, screen resolution fails to conform to a multiple of w:50 x h:50, w:100 x h:50, w:100 x h:100, or w:100 x h:200. I wonder whether this issue might be related to some sort of letterboxing issue in Tor Browser 9.5.3 (and 9.5.1 and 9.5).
Modified configuration about:config > layout.css.devPixelsPerPx Value 3.0 (screenshot 3) has none of the issues described in the preceding two configurations screen resolution fails to conform to a multiple of w:50 x h:100 when manually adjusting the window size, but and this configuration is not user-friendly because the size of Toolbar content, Bookmarks Toolbar content, inner window content, and the exterior window itself are excessively oversized and too large.
(2) Detailed Description of Issue —
In Tor Browser 9.5.3, 9.5.1, 9.5, 9.0.10, 9.0.9, and 9.0.4, the screen resolution in each version was tested and 24 corresponding screenshots were created to help define and resolve this issue in 9.5.3.
Throughout this submission, references to Tor Browser 9.5.3 collectively refer to versions 9.5.3, 9.5.1 and 9.5, and references to Tor Browser 9.0.10 collectively refer to versions 9.0.10, 9.0.9 and 9.0.4.
Tor Browser versions 9.5.3 and 9.0.10 are using the following Customize settings (screenshots 4, 5) when running the screen tests:
• Toolbars > ✓ Bookmarks Toolbar
• Density > Compact
• Drag ★Bookmarks Toolbar Items into the toolbar
• Use the default settings for Title Bar, Drag Space, and Themes.
In Tor Browser 9.5.3 and 9.0.10, default configuration about:config > layout.css.devPixelsPerPx Value -1.0 renders too small for comfortable viewing the Toolbars content, bookmarks folders and text appearing in the Bookmarks Toolbar, and inner window content. (screenshot 6). This default configuration causes unacceptable user eyestrain when using Tor Browser on a MacBook Air 13-inch laptop computer.
In Tor Browser 9.5.3, modified configuration about:config > layout.css.devPixelsPerPx Value 2.4 hits the sweet spot for making a slight but significantly beneficial enlargement in the size of the Toolbars content, bookmarks folders and text appearing in the Bookmarks Toolbar, and inner window content (screenshot 7). This modified configuration makes the viewing experience more comfortable and user-friendly by preventing user eyestrain when using Tor Browser on a MacBook Air 13-inch laptop computer.
However, when Tor Browser 9.5.3 is using modified configuration about:config > layout.css.devPixelsPerPx Value 2.4 when it starts, the window opens at screen resolution w:998 x h:599 (screenshot 7) across browser sessions, letterboxing displays the window at w:798 x h:599 (screenshot 8) across browser sessions when manually adjusting the size of the window, and Enter Full Screen opens the window at w:1198 x h:599 (screenshot 9) across browser sessions.
In contrast, when Tor Browser 9.0.10 is using modified configuration about:config > layout.css.devPixelsPerPx Value 2.4 when Tor Browser starts, the window opens at w:1000 x h:600 (screenshot 10) across browser sessions, letterboxing correctly displays the window at w:450 x h:450 (screenshot 11) across browser sessions when manually adjusting the size of the window, and Enter Full Screen correctly opens the window at w:1200 x h:600 (screenshot 12) across browser sessions.
In Tor Browser 9.5.3, setting modified configuration about:config > layout.css.devPixelsPerPx Value 3.0 (screenshot 13) and immediately quitting and restarting Tor Browser in that configuration opens the window at w:800 x h:500 (screenshot 14) across browser sessions, letterboxing displays the window at w:450 x h:450 (screenshot 15) across browser sessions when manually adjusting the size of the window, and Enter Full Screen opens the window at w:900 x h:500 (screenshot 16) across browser sessions.
However, in Tor Browser 9.5.3, modified configuration about:config > layout.css.devPixelsPerPx Value 3.0 is unsuitable because this configuration causes the content in the Toolbar and Bookmarks Toolbar to be excessively oversized and too large, and the size of content appearing in the inner window and the size of the exterior window itself are excessively oversized and too large (screenshot 17).
When Tor Browser 9.5.3 is using modified configuration about:config > layout.css.devPixelsPerPx Value 3.0 when Tor Browser starts, immediately changing the configuration from about:config > layout.css.devPixelsPerPx Value 3.0 to about:config > layout.css.devPixelsPerPx Value 2.4 (screenshot 18) without restarting Tor Browser instantaneously changes the screen resolution from size w:800 x h:500 (screenshot 19) to indicated test size w:1000 x h:600 (screenshot 20 ), letterboxing displays the window at indicated test size w:451 x h:500 (screenshot 21, 451x500) when manually adjusting the window size, and Enter Full Screen opens the window at indicated test size w:1200 x h:600 (screenshot 22).
However, during the browser session in the preceding paragraph, Tor Browser 9.5.3 renders the window at indicated test size w:1000 x h:600 only during that single browser session, and Enter Full Screen opens the window at indicated test size w:1200 x h:600 only during that single browser session because, after quitting and restarting Tor Browser 9.5.3, the window opens with configuration about:config > layout.css.devPixelsPerPx Value 2.4 and screen resolution w:998 x h:599 (screenshot 7), the window displays indicated test size w:449 x h:599 (screenshot 23) when manually adjusting the window size, and Enter Full Screen opens the window at indicated test size w:1199 x h:599 (screenshot 24).
The described issues are present in Tor Browser versions 9.5.3, 9.5.1, 9.5, but testing indicates they are not present in Tor Browser versions 9.0.10, 9.0.9, and 9.0.4.
Modified configuration about:config > layout.css.devPixelsPerPx Value 2.4 is compatible with Tor Browser 9.0.10, 9.0.9, and 9.0.4 and causes no letterboxing or screen resolution issues in those versions.
(3) Desired Outcome —
When Tor Browser is using Customize settings Toolbars>✓ Bookmarks Toolbar, Density>Compact, drag>★Bookmarks Toolbar Items into toolbar, and default settings>for Title Bar, Drag Space, and Themes, Tor Browser would render the following screen resolutions for each instance Tor Browser starts when it is using modified configuration about:config > layout.css.devPixelsPerPx Value 2.4:
• Screen resolution conforms to a multiple of w:50 x h:50, w:100 x h:100, or w:100 x h:200 across browser sessions.
• Screen resolution conforms to a multiple of w:50 x h:50, w:100 x h:50, w:100 x h:100, or w:100 x h:200 across browser sessions when manually adjusting the size of the window.
• Enter Full Screen opens the window at a multiple of w:100 x h:100 or w:100 x h:200 across browser sessions.
Platform: macOS Catalina Version 10.15.6, MacBook Air 13-inch laptop computer.
TorZillaPrint screen test: https://ghacksuserjs.github.io/TorZillaPrint/TorZillaPrint.html
