I am quite new to Qt and am in a situation where I want to use a model for my needs:
I have a dynamic number of instances of a subclass that need to be handled differently (different UI controls for each if it is selected). I want to get a list view where I can add new elements or delete old ones, as well as disabling/enabling existing ones.
Of course I want to rewrite as least of the code as possible, so I thought of utilizing the Listwidget and a ListModel to give some controls to the user. But how to link these (or better the items) to instances of the classes?
Do you know any tutorials on this?
I already looked in QtDemo and Google but I do not know the right words to search for
so I had no good results.
Basically what I think I need is a model item that accepts Collider* for its data.
But when I plug this into QStandardItem.setData() it says error: ‘QVariant::QVariant(void*)’ is private
So I found the solution to this problem.
As QStandardItems are capable of storing QVariants as data I wanted to store a pointer to my data in a QVariant. To achieve this I had to use Q_DECLARE_METATYPE(MyType*).
With this I was able to
MyType *MyInstance = new MyType;
QVariant data;
data.setValue(MyInstance);
QStandardItem *item = new QStandardItem("My Item");
item->setData(data);
standardModel->appendRow(item);
And the best is you can add as many types you want and let QVariant do the work to decide if it contains the type you wanted:
if(v.canConvert<MyType*>())
//Yes it is MyType
else if( v.canConvert<MyOtherType*>())
//Oh it is the other one
So finally this only requires to declare the meta type so you do not have to subclass any items.
Also you should read on the limitations of this here:
Q_DECLARE_METATYPE
qRegisterMetaType
Does this page answer your questions? There's an example of deriving a StringListModel item that you might be able to use as a template
Related
I’m trying to create a new dataset type Powerapps Component (PCF). For the moment I am using it to display a view of the records that are available in an entity in Microsoft Dynamics CRM.
I wish to make the view sort itself when I click on the grid column headers (in a similar way that the default CRM grid view does). I'm trying to figure out how to apply a sort to the dataset so that I can refresh it as indicated by the documentation for the dataset.refresh() function:
Refreshes the dataset based on filters, sorting, linking, new column.
New data will be pushed to control in another 'updateView' cycle.
The dataset object does have a “sorting” property, but changing its value and then refreshing the dataset doesn’t seem to have any effect. After the refresh, the sorting property reverts to the value it had before I changed it.
In short, the click handler for the grid header does something like the following bit of code. The refresh gets done and my updateView() function gets called as expected but the sorting was not applied.
dataset.sorting = [{name: 'createdon', sortDirection: 1}];
dataset.refresh();
Any help on getting the dataset sorting to work would be appreciated.
I've been experimenting with PowerApps Component Framework a little bit recently and I can confirm that the following code won't be working:
dataSet.sorting = [ { name: "columnName", sortDirection: 0 } ];
However, I managed to get this one working for me:
dataSet.sorting.pop(); // you may want to clean up the whole collection
dataSet.sorting.push({ name: "columnName", sortDirection: 0 });
I haven't really figured out the reason of this behavior. The sorting array may be implemented as some form of observable collection in the background.
I hope this will guide you to a functioning solution.
The documentation is pretty abysmal here, but here is my best guess from putting a few different pieces of information together.
TLDR: I think there is some kind of extra method that needs to be called on the .sorting property, but I can't find out what it is called. Maybe something like:
dataset.sorting.setSorting({name: 'createdon', sortDirection: 1});
I think you're going to have to try a bunch of likely method names and see what works.
Background and links:
The only reference I could find to dataset.sorting was from here:
In this preview for canvas apps, only a limited set of filtering and sortStatus methods are supported. Filter and sort can be applied to dataset on primary type columns except for the GUID. Filter and sorting can be applied in the same way as in model-driven apps.To retrieve the dataset with filtering and sorting information, call
the methods in context.parameters.[dataset_property_name].filtering
and context.parameters.[dataset_property_name].sorting, then invoke
the context.parameters.[dataset_property_name].refresh().
So it seems that the .filtering and .sorting properties are handled similarly, and that there are some methods attached to them, and only some are supported. That is about as vague as they could make it...
I did find an example of how .filtering is used:
_context.parameters.sampleDataset.filtering.setFilter({
conditions: conditionArray,
filterOperator: 1, // Or
});
There is a brief reference to .setFilter() in the docs, as well as FilterExpression
There is a SortStatus reference, but it doesn't have any corresponding methods explicitly called out. It is possible that this is not yet a supported feature in the public preview, or the documentation is lacking and the name and syntax of the method you need to call on .sorting is not yet documented.
I am trying to list the view template’s properties so we can compare them with another old template.
For example what model elements are hidden or have overrides in a given template or which Revit links have been hidden or overridden in a given template.
View Template
(https://www.google.com/search?q=view+template+revit&rlz=1C1GGRV_enUS770US770&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjLndrd2cTbAhVESq0KHX1cAPwQ_AUICygC&biw=1536&bih=824#imgrc=Q0v-pV7Nxl4kfM:)
I’m looking to devise a View Template Compare tool and access to the owner and creator of them.
public void ApplyViewTemplateToActiveView()
{
Document doc = this.ActiveUIDocument.Document;
View viewTemplate = (from v in new FilteredElementCollector(doc)
.OfClass(typeof(View))
.Cast<View>()
where v.IsTemplate == true && v.Name == "MyViewTemplate"
select v)
.First();
using (Transaction t = new Transaction(doc,"Set View Template"))
{
t.Start();
doc.ActiveView.ViewTemplateId = viewTemplate.Id;
t.Commit();
}
}
With Revit API you can access with:
GetTemplateParameterIds Method / ViewTemplateId Property
The Revit API exposes almost all the ViewTemplate properties.
For instance this method returns all the Visibility/Graphic Overrides for a specific category:
https://apidocs.co/apps/revit/2019/ed267b82-56be-6e3b-0c6d-4de7df1ed312.htm
The only thing I couldn't get for a ViewTemplate are the "includes", but all the rest seems to be there.
Update:
The list or properties "not included" can be retrieved with GetNonControlledTemplateParameterIds().
Yes, and no.
Yes, I guess you can use Forge Model Derivative API to export RVT file and then build a dashboard around the View Templates data. That's assuming that View Templates data actually gets exported when the model is translated. That data is not attached to any geometry so I would not be surprised if it was skipped. The question here is why? This is like renting a 16-wheel truck to move a duffel bag across the street.
No, if your intention is to directly interact with the RVT model. Forge can view it, but to push anything back or request changes to the model, is not available yet. Then again, I am not even sure that the view template data is available via model derivative exports.
This brings me another alternative. Why not just collect the data using Revit API, the standard way and then push it out to a Database and build on top of that? There is no reason to employ Forge for any of that.
Thanks Jeremy, I had dig into your amazing website and also some solution that Konrad post in the Dynamo Forum about this. In Revit seems pretty achievable, you filter the View that is View Template and then extracts these properties, is it correct?.
I am wondering if someone can point me in the right direction with Forge.
Some amazing guys are developing a BQL https://www.retriever.works/.
BQL(Building Query Language) is a query language for buildings, similar to how SQL is a query language for databases. It is fast and flexible. BQL helps improve efficiency for QA/QC (quality assurance and quality control), and building data extraction without leaving Revit. I am also trying these and I would like to understand if there are some works where I could start with Forge next week about this.
I am using Vaadin 8 NativeSelect as a dropdown for users to make selections. Each selection refers to an object instance that holds multiple pieces of data and I only want the dropdown to display one piece of identifying information pertaining to a single variable in that object however it doesn't seem like NativeSelect can handle Model and Presentation separately in an obvious way.
data class Consultant(
val name: String,
val id: Long
)
val consultantSelection = NativeSelect<Consultant>().apply {
setItems(consultantDao.getAll())
caption = "Select Consultant"
}
In my code, I create a NativeSelect handling a type of Consultant which then creates a dropdown menu that simply unpacks the contents of the respective Consultant objects as each selectable. I would like to only display the name of the Consultant in the selection.
Is there a way to achieve this?
You have to provide a setItemCaptionGenerator for this. Otherwise Vaadin falls back to the .toString() implementation.
There is a whole section about dealing with things around that in Vaadin Documentation
There is something I don't understand how to do with Gtkmm 3.
I have a custom business type that I have declared like this:
enum class Eurocents : int {};
I would like to render this type into a Gtk::TreeView which has a Gtk::ListStore as model. So I declare a Gtk::TreeModelColumn<Eurocents>, and add it to the model. I then append_column this model column to the Gtk::TreeView with an appropriate title.
I then append_row to the model and set the value corresponding to the column to (Eurocents)100.
The result I get is that the cell is displayed empty. Understandably so, because I would not expect Gtkmm to know how to render my arbitrary type.
I would like to instruct Gtkmm on how to render my type.
I already know how to display Glib types like Glib::ustring and formatting to Glib::ustring for display is possible, but it is not the subject of the question.
Is it possible to code columns that can display arbitrary types like this? And if so, how? What is required for sorting to work?
The most common, and easiest way, is to use a cell_data_func callback. For instance, you can create your own instance of a Gtk::TreeView::Column (the view column), pack a cell renderer (or more) into your Gtk::TreeView::Column, append your Gtk::TreeView::Column to the TreeView with Gtk::TreeView::append_column(), and call set_cell_data_func() on your Gtk::TreeView::Column():
https://developer.gnome.org/gtkmm/stable/classGtk_1_1TreeViewColumn.html#a3469e1adf42e5932ea123ec33e4ce4e1
You callback would then get the value(s) from the model and set the appropriate values of the properties of the renderer(s).
Here is an example that shows the use of set_cell_data_func(), as well as showing other stuff:
https://developer.gnome.org/gtkmm-tutorial/stable/sec-treeview-examples.html.en#sec-editable-cells-example
This link should also be useful:
https://developer.gnome.org/gtkmm-tutorial/stable/sec-treeview.html.en#treeview-cellrenderer-details
If you like, Gtk::TreeView::insert_column_with_data_func() makes this a little more concise: https://developer.gnome.org/gtkmm/stable/classGtk_1_1TreeView.html#a595dcc0b503a7c1004c296b82c51ac54
As for the sorting, you should be able to just call set_sort_func() to specify how the column is sorted: https://developer.gnome.org/gtkmm/stable/classGtk_1_1TreeSortable.html#a3a6454bd0a285324c71edb73e403cb1c
Then this regular sorting advice should apply: https://developer.gnome.org/gtkmm-tutorial/stable/sec-treeview-sort.html.en
I want to build custom filtering header for Vaadin tables.
Can you please give some examples or solution to this problem.
I want to add a combo box or check box that will refine the search in the table like Excel columns.
We faced the problem of adding custom filters for Vaadin Table in our project as well.
As a solution we added a dynamic filter form above the table. It has become flexible and agile enough to apply filters.
We created Vaadin Addon in order to share our solution - Lexaden Grid.
You can find more information by the following link:
http://www.lexaden.com/main/entry/lexaden_grid
At the moment it is quite hard to add a custom component to do filtering with to the header of a table. It would require you to make your own version of Table by inheritance/copy&paste (not sure what is enough), and that is something most people wan't to avoid at the moment if anyway possible. The current implementation of the Table component is one of the most complicated components of Vaadin. It is doable if you insist putting components in header, but prepare for some serious thinking to get things to work.
I'd suggest making the filtering of data in containers with components just next/above your table. Hiding the table header is sometimes acceptable if there's no crucial information shown there. If you want something precisely on the header, it would require some empty headers and CSS positioning components on correct place.
You can always group table and other filtering components to one CustomComponent for easier abstraction.
Book of Vaadin is a very good reference for vaadin implementation. The link consist of an example code like:
// Define the properties
table.addContainerProperty("lastname", String.class, null);
table.addContainerProperty("born", Integer.class, null);
table.addContainerProperty("died", Integer.class, null);
// Set nicer header names
table.setColumnHeader("lastname", "Name");
table.setColumnHeader("born", "Born");
table.setColumnHeader("died", "Died");
Is this what you ask for? If it isn't, can you please specify your question a bit more clearly?
edit: Vaadin Sampler also contains handful code samples.