I just found mention of how to keep background cell color even while hovering or selecting a row on a JFace TableViewer by using StyledCellLabelProvider.COLORS_ON_SELECTION. However, I am using a subclass of StyledCellLabelProvider - a DecoratingStyledCellLabelProvider.
Is there any way for me to use the StyledCellLabelProvider.COLORS_ON_SELECTION style bit? I don't see any constructors that take a style bit, and no method to set the style.
You can't set the flag but you can override the DecoratingStyledCellLabelProvider.paint method to simulate what it does:
#Override
protected void paint(final Event event, final Object element)
{
if ((event.detail & SWT.SELECTED) != 0)
{
event.detail &= ~SWT.SELECTED;
super.paint(event, element);
event.detail |= SWT.SELECTED;
}
else
super.paint(event, element);
}
This is just turning off the 'selected' flag during the paint so the row is treated as normal.
However I don't really recommend this (or COLORS_ON_SELECTION) as it does not work well on some platforms.
Related
This subject is driving my nuts. I've read virtually a hundred posts about it, but none of them reflects my situation. I'm using a plain simple RecyclerView in an app running on AndroidTV. To enable navigation, I've set
android:focusable="true"
Now, I can use DPAD to scroll inside the RecyclerView, nicely. My goal is to animate the highlighting of the currently focused item in the list. However, I can't seem to find any event which indicates a focus change.
I would very much appreciate a hint, how my code could be informed about a focus changed inside the list, programaticaly, and how to figure out which list items have gained/lost focus.
Thanks!
Finally, it turned out that the solution is fairly easy. I don't know, why it was hidden in front of my eyes. All I had to do was to view.setOnFocusChangeListener() inside onBindViewHolder like this:
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
...
view.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View view, boolean b) {
highlightEntry(view, b);
}
});
...
}
I am working on disabling copy/paste option menus on xamarin forms Entry, I am able to disable copy option using IsPassword=true attribute but this attribute also converts the normal input field to password field, which is not a requirement.
<Entry IsPassword="true" Placeholder="Password" TextColor="Green" BackgroundColor="#2c3e50" />
Thanks in advance.
This has to do with how Forms functions. Using iOS as the example here, the CanPerform override referred to in the other answer's Bugzilla issue is using the UIMenuController as the withSender and not the UITextField itself that might otherwise be expected. This is because the EntryRenderer class is a ViewRenderer<TView, TNativeView> type and subsequently is using whatever TNativeView (in this case, the UITextView) has in its CanPerform. Because nothing is going to be overridden by default, one still sees all of the cut/copy/paste options in the UIMenuController.
As a result, there would be a couple options. You could first make the modification where if you don't want copy/paste but are fine with getting rid of everything else, you can use UIMenuController.SharedMenuController.SetMenuVisible(false, false) in a custom renderer inheriting from EntryRenderer. If you look around on SO, there are similar questions where this is a possible route.
Alternatively, you can create a "true" custom renderer inheriting from ViewRenderer<TView, TNativeView> as ViewRenderer<Entry, YourNoCopyPasteUITextFieldClassName>. The class inheriting from UITextField can then override CanPerform as something like follows:
public override bool CanPerform(Selector action, NSObject withSender)
{
if(action.Name == "paste:" || action.Name == "copy:" || action.Name == "cut:")
return false;
return base.CanPerform(action, withSender);
}
This will require more effort because the custom renderer will not have the same behavior as the EntryRenderer, but as Xamarin.Forms is now open source, you could look to it for some ideas as to how the EntryRenderer functions normally. Something similar would likely have to be done for Android.
Edit: For Android, you can probably use this SO answer as a starting point: How to disable copy/paste from/to EditText
Another custom renderer, this time inheriting from ViewRenderer<Entry, EditText>, and create a class inside of it like this (in the most basic form):
class Callback : Java.Lang.Object, ActionMode.ICallback
{
public bool OnActionItemClicked(ActionMode mode, IMenuItem item)
{
return false;
}
public bool OnCreateActionMode(ActionMode mode, IMenu menu)
{
return false;
}
public void OnDestroyActionMode(ActionMode mode)
{
}
public bool OnPrepareActionMode(ActionMode mode, IMenu menu)
{
return false;
}
}
Then, in your OnElementChanged method, you can set the native control and the CustomSelectionActionModeCallback value:
protected override void OnElementChanged(ElementChangedEventArgs<Entry> e)
{
base.OnElementChanged(e);
if (Control != null)
{
Control.CustomSelectionActionModeCallback = new Callback();
}
}
Doing something like the following appears to disable all of the copy/paste/cut functionality on the custom entry as far as the toolbar goes. However, you can still long click to show the paste button, to which I've poked around a bit hadn't found an answer yet beyond setting LongClickable to false. If I do find anything else in that regard, I'd make sure to update this.
In my Android app I have an ImageView where I'd like the user to be able to fling it left/right/up/down to change the image (static maps) to the adjacent one. But in addition, I'd like pinch-zoom abilities and a map itself.
I can get either flinging OR pinch-zooming to work, but not together. I'm using GestureDetector (with a SimpleOnGestureListener) for the flinging. And I'm using ScaleGestureDetector (from Making Sense of Multitouch) for the scaling.
The difficulty is to determine which gesture listener to invoke upon a touch action. This is less a coding issue, but logic issue. Upon a single finger touch action, is it a fling or scale? Even when a pinch-zoom is used, the initial MotionEvent is ACTION_DOWN. I've been trying to use the image size (intrinsic or scaled?) as a decision point. But the initial scaling operation (when image size is intrinsic and I want to zoom on it) with ACTION_DOWN seems to escape me.
Has anyone tackled this successfully previously?
You can pass the events on to both gesture detectors.
Check http://developer.android.com/training/gestures/scale.html under "More complex scaling example":
public boolean onTouchEvent(MotionEvent event) {
boolean retVal = mScaleGestureDetector.onTouchEvent(event);
retVal = mGestureDetector.onTouchEvent(event) || retVal;
return retVal || super.onTouchEvent(event);
}
Of course given the bug Ratatat is referencing, super.onTouchEvent will never be called in the above example, which may or may not be fine, depending on your use case.
The idea of Ratatat's answer is OK but we should still pass events to the gestureDetector even if we don't want to scroll, or it will be messed up.
I ended up with something like this:
scaleDetector = new ScaleGestureDetector( ... );
gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
if (scaleDetector.isInProgress()) {
// don't allow scrolling while scaling
return false;
}
// handle scrolling
return true;
}
}
And then onTouchEvent's implementation should be like in aij's answer:
boolean result = scaleDetector.onTouchEvent(event);
result = gestureDetector.onTouchEvent(event) || result;
return result || super.onTouchEvent(event);
Finally found the answer on a link:
http://code.google.com/p/android/issues/detail?id=42591
#Override
public boolean onTouchEvent(MotionEvent event) {
boolean result = mScaleGestureDetector.onTouchEvent(event);
// result is always true here, so I need another way to check for a detected scaling gesture
boolean isScaling = result = mScaleGestureDetector.isInProgress();
if (!isScaling) {
// if no scaling is performed check for other gestures (fling, long tab, etc.)
result = mCommonGestureDetector.onTouchEvent(event);
}
// some irrelevant checks...
return result ? result : super.onTouchEvent(event);
}
I am using the GestureRecognizer to detect drag and pinch gestures.
The ManipulationStarted, ManipulationUpdated and ManipulationCompleted events provide the translation and scale values that are needed to pinch and drag.
However I cant figure out how to distinguish between drag (1 touch point) and pinch (2 touch points) gestures. There is no information about the number of touchpoints in GestureRecognizer.
How can I distinguish between drag and pinch with the GestureRecognizer?
Well, I feel it is very hacky (as most solutions seem to be for a useable WinRT app) but you can create a List<uint> to keep track of the number of pointers that are currently down on the screen. You would have to handle the PointerPressed event on whatever control you are interacting with (Let's say you are using a Canvas) to "capture" the pointers as they are pressed. That is where you would populate the List<uint>. Don't forget to clear the list at the end of the ManipulationCompleted event as well as any event that would fire upon the end of any gestures (like PointerReleased, PointerCanceled, and PointerCaptureLost). Maybe it would be a good idea to make sure the list is cleared in the ManipulationStarted event. Perhaps you can try that and see how that works for you.
In the ManipulationCompleted event, you can check if your List contains exactly 2 elements (PointerIds). If so, then you know it is a pinch/zoom.
Here is what it could look like:
private void Canvas_PointerPressed(object sender, PointerRoutedEventArgs e)
{
var ps = e.GetIntermediatePoints(null);
if (ps != null && ps.Count > 0)
{
this.gestureRecognizer.ProcessDownEvent(ps[0]);
this.pointerList.Add(e.Pointer.PointerId);
e.Handled = true;
}
}
private void gestureRecognizer_ManipulationCompleted(GestureRecognizer sender, ManipulationCompletedEventArgs args)
{
if (this.pointerList.Count == 2)
{
// This could be your pinch or zoom.
}
else
{
// This could be your drag.
}
// Don't forget to clear the list.
this.pointerList.Clear();
}
// Make sure you clear your list in whatever events make sense.
private void Canvas_PointerReleased(object sender, PointerRoutedEventArgs e)
{
this.pointerList.Clear();
}
private void Canvas_PointerCanceled(object sender, PointerRoutedEventArgs e)
{
this.pointerList.Clear();
}
I have been struggling with the same question for a few hours now and it looks WinRT platform does not provide that. What it instead provides is Delta.Rotation and Delta.Scale values in addition to Delta.Translation with the arguments to ManipulationUpdated callback.
If Delta.Rotation is 0 (or very close to zero - because it is a float value) and Delta.Scale is 1 (or very close to 1), you can conclude that a pinch operation is not the case and a drag operation is being carried otherwise it is a pinch operation. It is not the best you can get but it looks it is the only availability for the time being.
I want to write the contents of a per occasion active TextBox back to the bound property of the ViewModel when the user presses the key combination for save (Ctrl-S).
My Problem with it is, that I'm not able to trigger the execution of the binding so that the bound Text-Property reflects the contents of the TextBox.
-There seems to be no GetBinding-method. Therefore I can not get the Binding and execute it manualy.
-There is no Validate-method such as in WinForms which executes the Binding
-Giving focus to another control from within KeyDown seems not to work, the binding does not execute
How can I achieve this?
Take a look at Aaron's discussion about this in his WiredPrarie blog post : http://www.wiredprairie.us/blog/index.php/archives/1701
I think I understand your question better now. One way around this would be to use a sub-classed textbox with a new property like this from here:
public class BindableTextBox : TextBox
{
public string BindableText
{
get { return (string)GetValue(BindableTextProperty); }
set { SetValue(BindableTextProperty, value); }
}
// Using a DependencyProperty as the backing store for BindableText. This enables animation, styling, binding, etc...
public static readonly DependencyProperty BindableTextProperty =
DependencyProperty.Register("BindableText", typeof(string), typeof(BindableTextBox), new PropertyMetadata("", OnBindableTextChanged));
private static void OnBindableTextChanged(DependencyObject sender, DependencyPropertyChangedEventArgs eventArgs)
{
((BindableTextBox)sender).OnBindableTextChanged((string)eventArgs.OldValue, (string)eventArgs.NewValue);
}
public BindableTextBox()
{
TextChanged += BindableTextBox_TextChanged;
}
private void OnBindableTextChanged(string oldValue, string newValue)
{
Text = newValue ? ? string.Empty; // null is not allowed as value!
}
private void BindableTextBox_TextChanged(object sender, TextChangedEventArgs e)
{
BindableText = Text;
}
}
Then bind to the BindableText property.
Solution for command-instances
Here a solution I have found which is relatively leightweight, but also a bit "hackish":
btn.Focus(Windows.UI.Xaml.FocusState.Programmatic);
Dispatcher.ProcessEvent(CoreProcessEventsOption.ProcessAllIfPresent);
btn.Command.Execute(null);
First I give the focus to another control (In my case the button which has the bound command). Then I give the system time to execute the bindings and in the end I raise the command which is bound to the button.
Solution without bound commands
Give the Focus to another control and call the Dispatcher.ProcessEvent(...).
anotherControl.Focus(Windows.UI.Xaml.FocusState.Programmatic);
Dispatcher.ProcessEvent(CoreProcessEventsOption.ProcessAllIfPresent);
// Do your action here, the bound Text-property (or every other bound property) is now ready, binding has been executed
Please see also the solution of BStateham.
It's another way to solve the problem