Add VisibleItemModel #1845
Add VisibleItemModel #1845
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blammit
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| } | ||
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| */ | ||
| class VisibleItemModel : public QQmlInstanceModel |
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Just checking - what's the general policy of using private APIs? e.g. when we bump from Qt 6.6.3 > Qt 6.8 what source compatibility are we relying on?
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Generally we want to use the more established kind of private APIs, so that the instability is kept to a minimum, and only using them where absolutely necessary.
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Is there a reason why we can't use a public qt base model? eg. QAbstractItemModel
This allows items with preferredVisible=false to be filtered out from the model for a ListView. Otherwise, the view creates unused delegates, which are redundant and also will be problematic when key navigation is added as the user should not navigate through non-visible items. Part of #1732
VisibleItemModel automatically filters out non-visible items so that they are not part of any view that uses the model. This means that: - views won't need to create unnecessary delegates - when key navigation is added, it won't try to focus non-visible delegates VisibleItemModel does not currently support dynamic insertion/removal so it cannot be used in cases like SwipePageModel or NotificationLayer. Part of #1732
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| Q_OBJECT | ||
| Q_DECLARE_PRIVATE(VisibleItemModel) | ||
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| Q_PROPERTY(QQmlListProperty<QObject> sourceModel READ sourceModel NOTIFY sourceModelChanged DESIGNABLE false FINAL) |
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Does 'design mode' work for you? As long as I can remember, the 'design mode' button has been greyed out for me
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The DESIGNABLE probably isn't necessary, it came from a copy-paste.
| } | ||
| } | ||
| */ | ||
| class VisibleItemModel : public QQmlInstanceModel |
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Is there a reason why we can't use a public qt base model? eg. QAbstractItemModel
It needs to be a QQmlInstanceModel so that it can provide instances directly, unlike QAbstractItemModel. The QtQuick views have built-in behaviour to treat instance models differently; it can fetch delegate instances directly from the model, whereas when it uses a QAbstractItemModel, it will instantiate delegate instances instead. |
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