#454 Allow to move tabs

[asashnov]

Fixes #454

Public interface of tabbar.h changes:

• currentWidget() -> currentZimView() (because the method returned nullptr if library or setting page is current)
• widget(int) illiminated, replaced with closeTabsByZimId(id) because this is what it needed for;

TabBar Implementation changes:

• m_settingsIndex removed, not needed. Replaced to the usage of qobject_cast<> to determine the type of a specific tab widget, instead of trying to track it;
• fixed hardcoded conditions that the index 0 is the library page (it also can be moved);
• remove unused mp_contentManagerView property

Added Q_OBJECT macros in classes ContentManagerView and SettingsManagerView, otherwise qobject_cast doesn't work (https://wiki.qt.io/Coding_Conventions).

[asashnov]

The current implementation works, but has a bug:

Steps to reproduce:

• Run the app
• open Settings
• move Settings tab to the left (to the place of the library)
• open new tab (by +)

Actual result: Settings tab will be collapsed to the icon

[kelson42]

@asashnov Have put the PR to draft, so i can be polished before review.

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. It will be now be reviewed manually. Thank you for your contributions.

[kelson42]

@asashnov Works almost perfectly to my opinion. Only one point. Can you please make the library tab stick to the left (so effectively forbids to move a tab before)?

[kelson42]

Sticky library tab works perfectly. Thx!

[kelson42]

Have just rebased the branch.

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. It will be now be reviewed manually. Thank you for your contributions.

[asashnov]

The branch rebased on top of current master (d140601), multiple commits squashed to one commit.

[mgautierfr]

Code is good.

It is matter of taste/style but I prefer to use auto instead of being explicit on the type of the object.

The same way, I prefer

auto zv = currentZimView();
if (zv) {
    return zv->getWebView();
}
return nullptr;

to

if (ZimView *zv = currentZimView())
    return zv->getWebView();
return nullptr;

Also, I like to have a PR split is several logical commits (but squash commits fixing errors in previous commits of the same PR)

But I will not block the PR for that.
Code is good and functional.

[asashnov]

Replaced to auto in lines:

    } else if (ZimView *zv = qobject_cast<ZimView*>(w)) {

    ZimView *zv = qobject_cast<ZimView*>(mp_stackedWidget->widget(i));

because pointer type is clearly noted by qobject_cast.

In other cases we should be clear about what we want to get from a tab: QWidget, WebView or ZimView.

Splitted the change to 4 logical commits.

[asashnov]

Fixed compilation for all 4 commits after splitting the change.

[kelson42]

@asashnov Would you please rebase on master?

[asashnov]

@kelson42 rebased and tested, ready to merge.