Bugzilla

Here's a reduced testcase, I think, using the media query from comment 5.

STR here are:
1. Load the testcase in a fullscreen browser (wider than 767px)
2. Ctrl+P to print-preview the testcase (using default print settings, i.e. US Letter or A4, portrait-orientation).

After step 1, Firefox and Chrome both show "no" and only a single list-entry (in the browser-window).
After step 2:
* Firefox shows the same thing (still "no", still just 1 list-entry)
* Chrome's print-preview rendering shows "Yes" and 2 list entries; and Chrome's browser-tab (behind print-preview) continues to show "no" and shows 3 list entries.

So it looks like Chrome is firing the media query callback once when generating the printed document, and rendering that for print-preview, and then firing the media query callback again when restoring the original viewport settings for the regular browser-tab presentation.  Or something to that effect.

Here's a reduced testcase, I think, using the media query from comment 5.

STR:
1. Load the testcase in a fullscreen browser (wider than 767px)
2. Ctrl+P to print-preview the testcase (using default print settings, i.e. US Letter or A4, portrait-orientation).

After step 1, Firefox and Chrome both show "no" and only a single list-entry (in the browser-window).
After step 2:
* Firefox shows the same thing (still "no", still just 1 list-entry)
* Chrome's print-preview rendering shows "Yes" and 2 list entries; and Chrome's browser-tab (behind print-preview) continues to show "no" and shows 3 list entries.

So it looks like Chrome is firing the media query callback once when generating the printed document, and rendering that for print-preview, and then firing the media query callback again when restoring the original viewport settings for the regular browser-tab presentation.  Or something to that effect.

Here's a reduced testcase, I think, using the media query from comment 5.

STR:
1. Load the testcase in a fullscreen browser (wider than 767px)
2. Ctrl+P to print-preview the testcase (using default print settings, i.e. US Letter or A4, portrait-orientation).

After step 1, Firefox and Chrome both show "no" and only a single list-entry (in the browser-window).
After step 2, when the print-preview rendering appears:
* Firefox continues to show the same thing (still "no", still just 1 list-entry), in both the browser-tab and print-preview renderings.
* Chrome's print-preview rendering shows "Yes" and 2 list entries; and Chrome's browser-tab (behind print-preview) continues to show "no" and shows 3 list entries.

So it looks like Chrome is firing the media query callback once when generating the printed document, and rendering that for print-preview, and then firing the media query callback again when restoring the original viewport settings for the regular browser-tab presentation.  Or something to that effect.

Here's a reduced testcase, I think, using the media query from comment 5.

STR:
1. Load the testcase in a fullscreen browser (wider than 767px)
2. Ctrl+P to print-preview the testcase (using default print settings, i.e. US Letter or A4, portrait-orientation).

RESULTS:
After step 1, Firefox and Chrome both show "no" and only a single list-entry (in the browser-window).
After step 2, when the print-preview rendering appears:
* Firefox continues to show the same thing (still "no", still just 1 list-entry), in both the browser-tab and print-preview renderings.
* Chrome's print-preview rendering shows "Yes" and 2 list entries; and Chrome's browser-tab (behind print-preview) continues to show "no" and shows 3 list entries.

So it looks like Chrome is firing the media query callback once when generating the printed document, and rendering that for print-preview, and then firing the media query callback again when restoring the original viewport settings for the regular browser-tab presentation.  Or something to that effect.

Here's a reduced testcase, I think, using the media query from comment 5.

STR:
1. Load the testcase in a fullscreen browser (wider than 767px)
2. Ctrl+P to print-preview the testcase (using default print settings, i.e. US Letter or A4, portrait-orientation).

RESULTS:
After step 1, Firefox and Chrome both show "no" and only a single list-entry (in the browser-window).
After step 2, when the print-preview rendering appears:
* Firefox continues to show the same thing (still "no", still just 1 list-entry), in both the browser-tab and print-preview renderings.
* Chrome's print-preview rendering shows "Yes" and 2 list entries; and Chrome's browser-tab (behind print-preview) continues to show "no" and shows 3 list entries.

So it looks like Chrome is firing the media query listener-callback once when generating the printed document, and rendering that for print-preview, and then firing the media query callback again when restoring the original viewport settings for the regular browser-tab presentation.  Or something to that effect.

Here's a reduced testcase, I think, using the media query from comment 5.

STR:
1. Load the testcase in a fullscreen browser (wider than 767px)
2. Ctrl+P to print-preview the testcase (using default print settings, i.e. US Letter or A4, portrait-orientation).

RESULTS:
After step 1, Firefox and Chrome both show "no" and only a single list-entry (in the browser-window).
After step 2, when the print-preview rendering appears:
* Firefox continues to show the same thing (still "no", still just 1 list-entry), in both the browser-tab and print-preview renderings.
* Chrome's print-preview rendering shows "Yes" and 2 list entries; and Chrome's browser-tab (behind print-preview) continues to show "no" and shows 3 list entries.

So it looks like Chrome is firing the media query listener-callback once when generating the printed document (due to the viewport-size shrinking to below the media query's threshold), and then they render the resulting document for print-preview; and then they fire the media query callback again when restoring the original viewport settings for the regular browser-tab presentation.  Or something to that effect.