fix: apply selected paper size after printer settings rebuild

[18202781743]

Summary

• explicitly apply the selected paper size after rebuilding printer settings
• keep the preview and printer page layout consistent when the default item is a custom paper size
• add a regression test for restoring a custom paper-size selection

Tests

• cmake --build build -j6 --target ut-dtkwidget
• print-preview regression test: passed
• cmake --build build6 -j6 --target dtk6widget

Summary by Sourcery

Ensure the print preview uses the selected paper size consistently after printer settings are rebuilt.

Bug Fixes:

• Preserve and correctly apply a selected custom paper size when printer settings are rebuilt.

Tests:

• Add a regression test covering restoration of a custom paper-size selection after changing printers.

[sourcery-ai]

Sorry @18202781743, you have reached your weekly rate limit of 500000 diff characters.

Please try again later or upgrade to continue using Sourcery

[sourcery-ai]

Reviewer's guide (collapsed on small PRs)

Reviewer's Guide

Ensures the selected custom paper size is explicitly reapplied after printer settings are rebuilt and adds a regression test to lock in this behavior.

Sequence diagram for applying selected paper size after printer change

sequenceDiagram
    actor User
    participant DPrintPreviewDialog
    participant PaperSizeCombo

    User->>DPrintPreviewDialog:_q_printerChanged(index)
    DPrintPreviewDialog->>PaperSizeCombo:blockSignals(true)
    DPrintPreviewDialog->>DPrintPreviewDialog:rebuildPaperSizeList()
    note over DPrintPreviewDialog: current index may not change
    DPrintPreviewDialog->>DPrintPreviewDialog:matchFitablePageSize()
    DPrintPreviewDialog->>DPrintPreviewDialog:marginsUpdate(true)
    DPrintPreviewDialog->>PaperSizeCombo:blockSignals(false)

Loading

File-Level Changes

Change	Details	Files
Ensure selected paper size is reapplied when printer settings are rebuilt during printer change handling.	Call matchFitablePageSize() immediately after rebuilding the paper list in _q_printerChanged to explicitly apply the selected page size when combo-box signals are blocked Keep marginsUpdate(true) and signal unblocking logic intact so layout and behavior remain consistent with existing flow	src/widgets/dprintpreviewdialog.cpp
Add regression coverage to ensure custom paper-size selection is preserved and applied after printer changes.	Extend SPDX copyright range to 2026 to reflect ongoing maintenance Add testPaperSizeAppliedAfterPrinterChanged test to set a custom paper size, trigger printer change (with list rebuild), and assert that both the combo current text and printer pageSize remain on the custom size	tests/testcases/printpreview/ut_dprintpreviewdialog.cpp

---

Tips and commands

Interacting with Sourcery

• Trigger a new review: Comment @sourcery-ai review on the pull request.
• Continue discussions: Reply directly to Sourcery's review comments.
• Generate a GitHub issue from a review comment: Ask Sourcery to create an
  issue from a review comment by replying to it. You can also reply to a
  review comment with @sourcery-ai issue to create an issue from it.
• Generate a pull request title: Write @sourcery-ai anywhere in the pull
  request title to generate a title at any time. You can also comment
  @sourcery-ai title on the pull request to (re-)generate the title at any time.
• Generate a pull request summary: Write @sourcery-ai summary anywhere in
  the pull request body to generate a PR summary at any time exactly where you
  want it. You can also comment @sourcery-ai summary on the pull request to
  (re-)generate the summary at any time.
• Generate reviewer's guide: Comment @sourcery-ai guide on the pull
  request to (re-)generate the reviewer's guide at any time.
• Resolve all Sourcery comments: Comment @sourcery-ai resolve on the
  pull request to resolve all Sourcery comments. Useful if you've already
  addressed all the comments and don't want to see them anymore.
• Dismiss all Sourcery reviews: Comment @sourcery-ai dismiss on the pull
  request to dismiss all existing Sourcery reviews. Especially useful if you
  want to start fresh with a new review - don't forget to comment
  @sourcery-ai review to trigger a new review!

Customizing Your Experience

Access your dashboard to:

• Enable or disable review features such as the Sourcery-generated pull request
  summary, the reviewer's guide, and others.
• Change the review language.
• Add, remove or edit custom review instructions.
• Adjust other review settings.

Getting Help

• Contact our support team for questions or feedback.
• Visit our documentation for detailed guides and information.
• Keep in touch with the Sourcery team by following us on X/Twitter, LinkedIn or GitHub.

[18202781743]

/integrate

[github-actions]

AutoIntegrationPr Bot
auto integrate with pr url: deepin-community/Repository-Integration#4504
PrNumber: 4504
PrBranch: auto-integration-32683882202

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: 18202781743, BLumia, robertkill

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• debian/deepin/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment