Change behavior when selecting with shift + click

[kbengs]

This is consistent with Nautilus shift-click-select

[angsch]

• The return value is sometimes True, 1 or missing in some branches.

• I found a case that behaved differently from what I expected.

  1. Load a PDF with 4 pages.
  2. Select all pages through clicking on page 1, holding shift and clicking on page 4.
  3. Remove page 2 from selection by holding Control and clicking on page 2.
  4. Hold shift and click on page 3.

  All pages are selected. I expected that only the pages 1--3 are selected (which is what Nautilus selects). Other than that new selection works really smoothly, nice work.

[kbengs]

Thank you for testing.

The return value is sometimes True, 1 or missing in some branches.

Yes I know I haven't been consistent with the return value. Documentation I have found say that True should be returned to stop further processing. But 1 also works. I don't know if 1 is a old recommendation.
We still use some of the iconviews built in functions, therefore True or 1 is not always returned. (For example when a page is clicked it is selected and cursor is set there.)

Hold shift and click on page 3

It is behaving like Dolphin in this aspect. When shift is held, what is already selected does not get deselected. Imo this is better. The new drag-select also work the same way: when shift is pressed it does not deselect, but instead it allows you to select more pages.
(The result after step 4 on Nautilus on my machine is that only page 3 is selected)

[angsch]

It is behaving like Dolphin in this aspect. [...]

(The result after step 4 on Nautilus on my machine is that only page 3 is selected)
The behavior of Nautilus on your system surprises me. I wonder if it is triggered by custom settings or the theme. I had check with Dolphin and in a fresh install I get the behavior you describe. So please ignore my comment.

[jeromerobert]

It looks good and ready for merge.