[Interest] Implementing tag cloud with QML

[Ben Lau]

May be it is not a perfect solution, I usually fix this kind of problem by
adding a timestamp of last update  ( (new Date()).getTime() ) . Then force
those items to refresh on value changes.

On 28 September 2015 at 18:36, Nuno Santos <nunosantos at imaginando.pt> wrote:

> Ben,
>
> Item is of class Item
> itemList model is of class QList<Item*>
>
> Item has the property tags which is of type QStringList
> Each item has ItemManager, the holder of itemList model, as parent
>
> On toggleTag I’m doing this:
>
> void DRCPatch::toggleTag(QString tag)
> {
>     if (_tags.contains(tag))
>         _tags.removeOne(tag);
>     else
>         _tags.append(tag);
>
>     emit _manager->tagsChanged();
> }
>
> And in fact, the model is returned. I have confirmed that the model
> property has been called. However, ListView doesn’t update or re-layout if
> the items are exactly the same.
>
> If here I do _tags.append(“something”) it will update and behave as
> expected.
>
> QStringList ItemManager::tags()
> {
>     return _tags;
> }
>
> Any ideas on how to work around this?
>
> Regards,
>
> Nuno
>
> On 28 Sep 2015, at 10:54, Ben Lau <xbenlau at gmail.com> wrote:
>
> How do you use the toggleTag? And what is the data type of element in
> itemList.model?
>
>
>
> On 28 September 2015 at 17:19, Nuno Santos <nunosantos at imaginando.pt>
> wrote:
>
>> Hi,
>>
>> I was trying to implement a tag cloud with a ListView but I'm facing some
>> unexpected problems. My idea was the following:
>>
>> A ListView would have a model of tags, based on a QStringList. Other list
>> view would have items (custom model), each item would have associated tags.
>> I want to concentrate the tags in a single list in the UI. So, when you
>> select an item, it will display all the tags, and the ones which are
>> present in that item would get highlighted.
>>
>> Every time I click a tag, it will toggle that tag for the respective
>> item. The problem is that for some reason, ListView seems to cache the data
>> model and thus it doesn’t get redrawn. Because the tags are the exactly the
>> same. What changed was item tags list.
>>
>> Is there anyway to bypass the model cache or force the ListView to
>> redraw? I can’t find any suitable method on ListView documentation.
>>
>> I’m not finding an obvious solution for this problem and I believe that
>> is a simple solution for it. Any ideas?
>>
>> ListView {
>> id: tagsList
>> model: tags
>> delegate: Rectangle {
>>    color: "transparent"
>>    border.color: "white"
>>    border.width: 1
>>
>>    Text {
>>        id: tagLabel
>>        color: "gray"
>>        text: "#"+modelData
>>        Component.onCompleted: {
>>            var tags = itemList.model[itemList.currentIndex].tags;
>>
>>            for (var i=0;i<tags.length;i++)
>>            {
>>                if (tags[i]==modelData)
>>                    color = "white"
>>            }
>>        }
>>    }
>>
>>    MouseArea {
>>        anchors.fill: parent
>>        onClicked:
>> itemList.model[itemList.currentIndex].toggleTag(modelData)
>>    }
>> }
>> }
>>
>> Thanks in advance,
>>
>> Regards,
>>
>> Nuno
>>
>> _______________________________________________
>> Interest mailing list
>> Interest at qt-project.org
>> http://lists.qt-project.org/mailman/listinfo/interest
>>
>>
>
>
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