So I've got a GDK activity which loads a CardScrollView, it's working fine. However this list can be very long so I'm paginating in the JSON, so only the first 20 or so items are returned. What I'm trying to do is so when the user gets to the end of the list, they "overpull" and see more items show up. Loading the initial list works fine:
mAdapter = new CardCursorScrollAdapter();
mCardScrollView = (CardScrollView)rootLayout.findViewById(R.id.card_scroll_view);
mCardScrollView.setAdapter(mAdapter);
LoaderManager loaderManager = getLoaderManager();
loaderManager.initLoader(LOADER_ID, null, mCallbacks);
However I haven't been able to solve two problems: first, how to detect the over-pull, and second, how to update the CardScrollView with my additional data.
You can add a Card at the end of your dataset with a loading Text. When you reach this card (you can detect it with the OnItemSelectedListener) call the loader to load the next page. When the loading is finished, call the notifyDataSetChanged of your adapter to refresh the scrollview.
hope this will help.
Related
I have a little problem that I've been facing for about a week now.
I have a ListView in qt and this list is filled from c++ class. The code right now looks something like this:
stackView.push("pageWithList.qml")
stackView.currentPage.init(att)
//att is the information about from which page the page with list was pushed
Then in the pageWithView I have
Component.onCompleted: {
device.setStatusBarColor(desiredColor);
}
and in init function it looks like this:
function init(pScreenType) {
screenType = pScreenType;
switch (screenType) {
/*
*case for each type of screen from which I can get to this page
*/
case type:
list.model = app.page.getModel();
break;
}
}
In the getModel c++ method about 1000 items are returned. Now the problem is tha it takes about a second to load all the items and output for the user looks like this:
They click button moving them to the page with list
The status bar color changes
After one second of loading of the list view the page changes to desired page
Now I want the steps 2 and 3 to be swapped so the color of the status bar changes after the page changes -> after the list model is loaded.
I have tried everything that was in my power, searched whole google, qt documentation and didnt find a soultion to this. If anyone has any advice or a solution or just an inspiration of solving this problem I would be grateful.
I want to have the android back button to close the app if the user is on one of the two main pages. Both pages can be navigated to with two tabs button, which are shown on those both pages. But on any other pages I want to keep normal stack pages behaviour.
I read about registerBackButtonAction and also got some information in this thread concerning Ionic 1.
I created a custom behaviour to close the app:
private registerSpecificActionOnBackButton = () => {
if(this.platform.is('android')||this.platform.is('windows')){
this.platform.registerBackButtonAction(function(e){
this.platform.exitApp();
}.bind(this),101);
}
}
My idea is to call the registerSpecificActionOnBackButton() function in the ionViewWillEnter() function on the pages where this behaviour is needed.
But I don't manage to cancel that behaviour on the ionViewWillLeave() function with a deRegisterSpecificActionOnBackButton() function, I've tried among other things:
private deRegisterSpecificActionOnBackButton = () => {
if(this.platform.is('android')||this.platform.is('windows')){
this.platform.registerBackButtonAction(function(e){return true},101);
}
}
Or
private deRegisterSpecificActionOnBackButton = () => {
if(this.platform.is('android')||this.platform.is('windows')){
this.platform.registerBackButtonAction(function(event){event.unbind()},101);
}
}
But I happen to be stuck. Has anyone any idea about canceling a custom registerBackButtonAction?
I've managed to make this work as I expect: When the app is on one of the pages that can be reached thru the tabs menu, it closes when the back button is hitten (on Android).
First, forget about the registerBackButtonAction() for the moment because as quoting what is explained in this thread of 2016-08-05:
it suggests not trying to override the default back button behavior.
So I've looked for other solutions. I've found one that is not really clean but works.
To begin with, I looked if I could reset the stack with the NavControler using remove(startIndex, removeCount, opts). But that doesn't work out because the two main pages are embeded in the tab page (like it is shown there).
So when you're on one of those pages the NavController is a Tab and the parent of that is a Tabs.
In Tabs there is a Array variable named _selectHistory. The _selectHistory array seems to have a role similar to the stack. So when navigating from one page to another using the two tab buttons, one can see in a console.info(this.[NavControler var of the page].parent._selectHistory) that the array grows as the tab buttons are hitten alternatively. And when trying on a real device, the back button take you back switching from one page to another until the array is empty and then the next back button hit closes the app.
Hence I thought: Let see what happens if I override the value of that array. It cannot be done thru a function to apply on a Tabs object (unlike what is possible with NavController).
So in the Page concerning my pages embedded in the Tab page, I added the following in ionViewWillEnter():
ionViewWillEnter(){
this.navCtrl.parent._selectHistory=[];
}
This.navCtrl is my NavController object passed in the constructor of the page.
That's it.
Let's say that I have a group of radio items in a wxMenu. I know that exactly one of these will be checked at any given time.
Does the wxMenu or some other construct hold onto the index of the checked item, or do I need to call the isChecked on each radio item till I find the checked element to find it's index?
I've asked this question about how to do that, but I'd much prefer wxWidgets saved me from doing that everywhere.
No, saving the index of the last selected item (as shown in ravenspoint's answer) or using wxMenuBarBase::IsChecked() until you find the selected radio button is the only way to do it.
For wxWidgets to provide access to the currently selected button it would need not only to store it (which means not forgetting to update not only when the selected changes, but also when items are inserted into/deleted from the menu, so it's already not completely trivial), but to somehow provide access to the radio items group you're interested in, which would require being able to identify it and currently there is no way to do it and adding it isn't going to be particularly simple.
What could be done easily, however, is writing a reusable function int GetIndexOfSelectedRadioItem(int firstItem) that would start at the given item and call IsChecked() on subsequent items until it returns true and return the offset of the item. You should be able to do it in your own code, but if you'd like to include such function in wxWidgets itself (as a static wxMenuBar method, probably), please don't hesitate to send patches/pull requests doing it!
It is easy enough to roll your own.
Bind an event handler to wxEVT_COMMAND_RADIOBUTTON_SELECTED for every button. In the handler, extract the ID of the selected radio button and store it somewhere.
Like this:
ResolMenu = new wxMenu();
ResolMenu->AppendRadioItem(idRcvLoRez,"Low Resolution");
ResolMenu->AppendRadioItem(idRcvMeRez,"Medium Resolution");
ResolMenu->AppendRadioItem(idRcvHiRez,"High Resolution");
ResolMenu->Check( idRcvLoRez, true );
Bind(wxEVT_MENU,&cFrame::onRcvRez,this,idRcvLoRez);
Bind(wxEVT_MENU,&cFrame::onRcvRez,this,idRcvMeRez);
Bind(wxEVT_MENU,&cFrame::onRcvRez,this,idRcvHiRez);
void onRcvRez( wxCommandEvent& event )
{
myRezID = event.GetId();
I'm selecting and loading some big Dicom files on my program. The whole loading process takes a long time(depends on the number of files, but the whole process can take more than minutes if the files are many). I want show a "waiting symbol" or something like that when the file uploading is going on. I searched for it, but I didn't get anything definite.
My code for the selection and uploading part is as below:
void MainWindow::showTheSelectedList()
{
QFileDialog * fileDialog = new QFileDialog(this);
fileDialog->setFileMode(QFileDialog::ExistingFiles);
QListView* list = fileDialog->findChild<QListView*>("listView");
if(list)
{
list->setSelectionMode(QAbstractItemView::MultiSelection);
}
QTreeView* tree = fileDialog->findChild<QTreeView*>();
if(tree)
{
tree->setSelectionMode(QAbstractItemView::MultiSelection);
}
if(fileDialog->exec())
{
if(fileDialog->selectedFiles().size()>0)
{
int listsize=stringList.size();
for(int i=0;i<listsize;i++)
{
// get the name of the file
// check if the file is dicom
// upload if the file is dicom
// after uploading, get the pixel data of that file
// use the pixel data and make a icon out of it
//then insert the icon in an a QTablewView
}
}
}
//show the QtableView
}
Could you please instruct me where and how I can show the waiting sign or symbol while the uploading part is running?
Thanks
I think you are looking for the QProgressBar class. The documentation makes it clear below. You will need to set up the minimum and maximum values, and it will do the job for you.
The QProgressBar widget provides a horizontal or vertical progress bar.
A progress bar is used to give the user an indication of the progress of an operation and to reassure them that the application is still running.
The progress bar uses the concept of steps. You set it up by specifying the minimum and maximum possible step values, and it will display the percentage of steps that have been completed when you later give it the current step value. The percentage is calculated by dividing the progress (value() - minimum()) divided by maximum() - minimum().
You can specify the minimum and maximum number of steps with setMinimum() and setMaximum. The current number of steps is set with setValue(). The progress bar can be rewound to the beginning with reset().
If minimum and maximum both are set to 0, the bar shows a busy indicator instead of a percentage of steps. This is useful, for example, when using QNetworkAccessManager to download items when they are unable to determine the size of the item being downloaded.
I do not think much more details can be provided based on the question as the worker loop seems to be commented without actual code being provided in there, but this documentation should make it clear either way.
Note that I would personally even move the worker loop into an own worker thread if it is that hefty that it deserves a progressbar. As for the progressbar, you would probably write something like this:
QProgressBar bar(this);
bar.setRange(maximum, maximum);
bar.setValue(minimum);
bar.show();
Dialog box:
My novice suggestion would be to use progress bar inside your for loop and increment the progress bar as each file finishes loading.
Let me know if you need more detail.
Titanium SDK version: 1.7.0
iPhone SDK version: 4.2
I am developing an iOS app using Appcelerator.
In this app I got a window that contains a table of contact data.
The user can click an item in this table and a new window opens up where they can
edit the contact details and then click save.
After the user clicked save I want the table in the parent window to update its data for the clicked row with the info sent back from the edit window.
My question is. How can I update the labels in a specific row if I got the row index?
I am planning to make this update from a custom event so I will not be using e.index only the "saved" index number for example 5.
I know there is a function called "updateRow" but I seem to only be able to update title of the row not its child elements.
Thankful for all input!
Here is the approach I would take.
Assumptions
win1 contains the table (table1) and
an array that contains rows that you
can update (data)
win2 is where the
editing occurs
On the 'save' button click in win2, fire an event with the updated contact details before you close the window;
Ti.App.fireEvent('contact.change' , updatedContactObject );
// Do database save here if required
win2.close();
Add an eventListener in win1:
Ti.App.addEventListener( 'contact.change' , function(e){
var updatedContactObject = e.updatedContactObject;
//
// update the array and the row here
//
data[ updatedContactObject.id ] = updatedRowData;
table1.setData(data);
});
In my experience it is best to tableView.setData(rowArray) whenever you make a change, rather than selectRow, updateRow, etc. Regarding the actual row elements, you should be able to navigate by using row.children[x].children[x]. The problem is that you will have to pay close attention to the hierarchy. Let us know if you find a better way!