In my app, I have a searchbox which allows users to filter as they type. For some reason I can't get an InfinteProgress to properly display while the filtering is being executed.
Here's my code:
Pass 1
public void renderForumList(){
try{
magnify = mStateMachine.findForumSearchIcon(form);
}catch(NullPointerException ex){
System.out.println("User typed additional character in search term before previous term finished executing");
}
InfiniteProgress infi = new InfiniteProgress();
magnify.getParent().replace(magnify, infi, null);
Display.getInstance().invokeAndBlock(new Runnable() {
#Override
public void run() {
for (int i = 0;i < containerStates.length;i++){
if(containerStates[i] != listItems[i].isVisible()){
listItems[i].setHidden(!containerStates[i]);
listItems[i].setVisible(containerStates[i]);
}
}
Display.getInstance().callSerially(new Runnable() {
#Override
public void run() {
mStateMachine.findForumsListComponent(form).animateLayout(200);
mStateMachine.findContainer2(form).replace(infi, magnify, null);
}
});
}
});
}
In this version, the infinite progress shows up in the proper position, but it doesn't spin.
Pass 2
public void renderForumList(){
try{
magnify = mStateMachine.findForumSearchIcon(form);
}catch(NullPointerException ex){
System.out.println("User typed additional character in search term before previous term finished executing");
}
InfiniteProgress infi = new InfiniteProgress();
magnify.getParent().replace(magnify, infi, null);
for (int i = 0;i < containerStates.length;i++){
if(containerStates[i] != listItems[i].isVisible()){
listItems[i].setHidden(!containerStates[i]);
listItems[i].setVisible(containerStates[i]);
}
}
mStateMachine.findForumsListComponent(form).animateLayout(200);
mStateMachine.findContainer2(form).replace(infi, magnify, null);
}
}
}
In this version, the magnifier icon just flashes briefly, but the InfiniteProgress spinner is never visible.
I get the same results on the simulator and on an Android device.
How can I get the InfiniteProgress to spin while the search is taking place?
invokeAndBlock opens a new thread and thus violates the EDT as you access UI components on a separate thread.
Try using callSerially instead to postpone the following code into the next EDT cycle although I'm not sure that will help as everything is still happening on the EDT.
Alternatively I'm guessing the method isVisible takes time, so you can enclose that call alone in invokeAndBlock.
To understand invokeAndBlock check out the developer guide https://www.codenameone.com/manual/edt.html
Related
Although the following question has been partly answered a number of times over the past decade, C# has changed significantly in the past few years to include better constructs for handling events, tasks, and the like. What is the current best suggested way to convert the following procedural code into code appropriate for a form, i.e., code to avoid busy waiting and keeping the computer responsive? Please provide complete code. I have found that mere suggestions usually require a lot more follow up for full understanding.
The form consists of a textbox (NameBox) where the name is displayed and two buttons (ButtonM and ButtonF) labeled "Male" and "Female" which when pressed do the functions described below. I've left out any declaration of the buttons since their definition is part of the solution I hope you can provide.
public class Question
{
static string[] names = {"Steve", "Lois", "Doug"};
static char[] genders = new char[names.Length];
public static void GetGenders (string[] names)
{
// Something 1
for (int i = 0; i < names.Length; i+) {
NameBox.Text = names[i];
// Wait for user to press Male or Female button;
// if (ButtonM pressed) genders[i] = 'M';
// if (ButtonF pressed) genders[i] = 'F';
}
// Something 2
}
}
Thanks for your time and effort.
I wasn't very clear on what I was asking. Below is the code I would have used 4 years ago. My question is "Is there a better way using the current C# language to accomplish this?"
public partial class Form1 : Form
{
static string[] names = {"Steve", "Lois", "Doug"};
static char[] genders = new char[names.Length];
public static char ch;
public Form1 ()
{
InitializeComponent();
}
private void ShownForm (object sender, EventArgs e)
{
GetGenders(names);
}
private TaskCompletionSource<bool> clickWaitTask;
public async void GetGenders (string[] names)
{
// Something 1
for (int i = 0; i < names.Length; i++) {
// Create a new TCS so that each time this logic is run,
// it will wait for the click to occur.
clickWaitTask = new TaskCompletionSource<bool>();
textBoxName.Text = names[i];
Application.DoEvents();
// Wait for user to press Male or Female button;
await clickWaitTask.Task;
textBoxResult.Text = ch.ToString();
}
// Something 2
Application.Exit();
}
// This task will only complete when TrySetResult is called
// on the TCS object.
private void ButtonClick (object sender, EventArgs e)
{
ch = (sender == buttonMale ? 'M' : 'F');
clickWaitTask.TrySetResult(true);
}
}
}
I am unhappy with having to create and remove a task for every iteration of the loop. Without involving a third task in the loop, is there a simpler way to just block the looping thread until another thread (the one with the button) can unblock it?
Where should I put this chunk of code in order the listener function works every time I enter the app from the deep link?
Now in my unity mobile app I have this code in the initial load, however it does not work well.
The first case of entering the app from the deep link is not being handled. Only after initial load when I click the deep link my listener function works (as the listener is already set).
Is there any solution to this issue?
void Start()
{
DynamicLinks.DynamicLinkReceived += OnDynamicLink;
}
// Display the dynamic link received by the application.
void OnDynamicLink(object sender, EventArgs args)
{
var dynamicLinkEventArgs = args as ReceivedDynamicLinkEventArgs;
Debug.LogFormat("Received dynamic link {0}", dynamicLinkEventArgs.ReceivedDynamicLink.Url.OriginalString);
}
Test this, feel free to edit.
void Start()
{
StartCoroutine(WaitLoader()); //Loader
}
public void trueAwoken()
{
DynamicLinks.DynamicLinkReceived += OnDynamicLink;
}
public IEnumerator WaitLoader()
{
int i = 0;
while (i < 5) // Potential for true load state 5 (increase this 0-1000+?, it depends on your build?)
{
i++;
//Debug.Log("Waiting: " + i + "/" + Time.deltaTime);
yield return new WaitForFixedUpdate();
}
trueAwoken();
}
First time writing an AsyncTask and I seem to have a subtle design flaw that prevents both ProgressDialog, ProgressBar, and even Log.d() from working properly. I suspect that somehow I am not actually creating a new thread/task.
Short: the symptoms
A ProgressDialog is created in the constructor, and the code orders Android to show it in onPreExecute(), but the dialog never shows.
onProgressUpdate() is supposed to execute whenever I call publishProgress() from within doInBackground(), correct? Well, it doesn't. Instead, it executes when doInBackground() completes.
Long: investigations
Things I have verified through the emulator and, when possible, on a phone:
onPreExecute() is definitely called
the progress bar is not reset until after doInBackground() completes
update_dialog.show() is definitely executed, but the dialog does not appear unless I remove the .dismiss() in onPostExecute(); I imagine dialog is, like the progress bar, not shown until after doInBackground() completes, but is naturally immediately dismissed
the code will happily show dialogs when no computation is involved
doInBackground() definitely invokes publishProgress()
when it does, onProgressUpdate() does not execute immediately! that is, I have a breakpoint in the function, and the debugger does not stop there until after doInBackground() completes! (perhaps this is a phenomenon of the debugger, rather than doInBackground(), but I observe the same symptoms on a mobile device)
the progress bar gets updated... only after doInBackground() completes everything
similarly, the Log.d() data shows up in Android Monitor only after doInBackground() completes everything
and of course the dialog does not show up either in the emulator or on a device (unless I remove .dismiss() from onPostExecute())
Can anyone help find the problem? Ideally I'd like a working dialog, but as Android has deprecated that anyway I'd be fine with a working progress bar.
Code
Here are the essentials, less the details of computation &c.:
Where I call the AsyncTask from the main thread:
if (searching) { // this block does get executed!
Compute_Task my_task = new Compute_Task(overall_context, count);
my_task.execute(field, count, max_x, max_y);
try { result = my_task.get(); } catch (Exception e) { }
}
The AsyncTask itself:
private class Compute_Task extends AsyncTask<Object, Integer, Integer> {
public Compute_Task(Context context, int count) {
super();
current_positions = 0;
update_dialog = new ProgressDialog(context);
update_dialog.setIndeterminate(true);
update_dialog.setCancelable(false);
update_dialog.setTitle("Thinking");
update_dialog.setMessage("Please wait");
}
protected void onPreExecute() {
super.onPreExecute();
update_dialog.show();
ProgressBar pb = ((ProgressBar) ((Activity) overall_context).findViewById(R.id.progress_bar));
pb.setMax(base_count);
pb.setProgress(0);
}
protected void onPostExecute() {
super.onPostExecute();
update_dialog.dismiss();
}
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
ProgressBar pb = ((ProgressBar) ((Activity) overall_context).findViewById(R.id.progress_bar));
pb.setMax(base_count);
pb.incrementProgressBy(1);
Log.d(tag, values[0].toString());
}
protected Integer doInBackground(Object... params) {
Integer result = compute_scores(
(boolean[][]) params[0], (Integer) params[1], (Integer) params[2], (Integer) params[3], 0)
);
return result;
}
public int compute_scores(boolean[][] field, int count, int max_x, int max_y, int level) {
int result, completed = 0;
switch(count) {
// LOTS of computation goes on here,
// including a recursive call where all params are modified
if (level == 0)
publishProgress(++completed);
}
}
ProgressDialog update_dialog;
}
Turns out this is basically the same issue as the one given here. The "fatal" line is this one:
try { result = my_task.get(); } catch (Exception e) { }
Apparently this puts the UI thread into deep sleep. One should not use get() with an AsyncTask unless one is willing to suspend the UI thread. We have to perform a little magic in onPostExecute() instead.
Although it turns out that this was a duplicate, I didn't find it until after I wrote it, because I didn't realize the thread was blocking.
I want get text string shown in a textview in LinearLayout. can espresso do that? If not, is there other way to do that or can I use android api in espresso test case? I am using API 17 18 or newer, espresso 1.1(It should be the latest one.). I have no clue about this. Thanks.
The basic idea is to use a method with an internal ViewAction that retrieves the text in its perform method. Anonymous classes can only access final fields, so we cannot just let it set a local variable of getText(), but instead an array of String is used to get the string out of the ViewAction.
String getText(final Matcher<View> matcher) {
final String[] stringHolder = { null };
onView(matcher).perform(new ViewAction() {
#Override
public Matcher<View> getConstraints() {
return isAssignableFrom(TextView.class);
}
#Override
public String getDescription() {
return "getting text from a TextView";
}
#Override
public void perform(UiController uiController, View view) {
TextView tv = (TextView)view; //Save, because of check in getConstraints()
stringHolder[0] = tv.getText().toString();
}
});
return stringHolder[0];
}
Note: This kind of view data retrievers should be used with care. If you are constantly finding yourself writing this kind of methods, there is a good chance, you're doing something wrong from the get go. Also don't ever access the View outside of a ViewAssertion or ViewAction, because only there it is made sure, that interaction is safe, as it is run from UI thread, and before execution it is checked, that no other interactions meddle.
If you want to check text value with another text, you can create Matcher. You can see my code to create your own method:
public static Matcher<View> checkConversion(final float value){
return new TypeSafeMatcher<View>() {
#Override
protected boolean matchesSafely(View item) {
if(!(item instanceof TextView)) return false;
float convertedValue = Float.valueOf(((TextView) item).getText().toString());
float delta = Math.abs(convertedValue - value);
return delta < 0.005f;
}
#Override
public void describeTo(Description description) {
description.appendText("Value expected is wrong");
}
};
}
I'm implementing a DynamicItemStart button inside a Menu Controller. I'm loading the dynamic items for this button when Visual Studio starts. Everything is loaded correctly so the initialize method is called an I see all the new items in this Dynamic button. After the package is completely loaded I want to add more items to this Dynamic button, but since the package is already loaded the initialize method is not called again and I cannot see the new items in this Dynamic button. I only see the ones that were loaded when VS started.
Is there any way that I can force the update of this Dynamic button so it shows the new items?. I want to be able to update the VS UI after I added more items but outside the Initialize method.
The implementation I did is very similar to the one showed on this msdn example:
http://msdn.microsoft.com/en-us/library/bb166492.aspx
Does anyone know if an Update of the UI can be done by demand?
Any hints are greatly appreciated.
I finally got this working. The main thing is the implementation of a derived class of OleMenuCommand that implements a new constructor with a Predicate. This predicate is used to check if a new command is a match within the DynamicItemStart button.
public class DynamicItemMenuCommand : OleMenuCommand
{
private Predicate<int> matches;
public DynamicItemMenuCommand(CommandID rootId, Predicate<int> matches, EventHandler invokeHandler, EventHandler beforeQueryStatusHandler)
: base(invokeHandler, null, beforeQueryStatusHandler, rootId)
{
if (matches == null)
{
throw new ArgumentNullException("Matches predicate cannot be null.");
}
this.matches = matches;
}
public override bool DynamicItemMatch(int cmdId)
{
if (this.matches(cmdId))
{
this.MatchedCommandId = cmdId;
return true;
}
this.MatchedCommandId = 0;
return false;
}
}
The above class should be used when adding the commands on execution time. Here's the code that creates the commands
public class ListMenu
{
private int _baselistID = (int)PkgCmdIDList.cmdidMRUList;
private List<IVsDataExplorerConnection> _connectionsList;
public ListMenu(ref OleMenuCommandService mcs)
{
InitMRUMenu(ref mcs);
}
internal void InitMRUMenu(ref OleMenuCommandService mcs)
{
if (mcs != null)
{
//_baselistID has the guid value of the DynamicStartItem
CommandID dynamicItemRootId = new CommandID(GuidList.guidIDEToolbarCmdSet, _baselistID);
DynamicItemMenuCommand dynamicMenuCommand = new DynamicItemMenuCommand(dynamicItemRootId, isValidDynamicItem, OnInvokedDynamicItem, OnBeforeQueryStatusDynamicItem);
mcs.AddCommand(dynamicMenuCommand);
}
}
private bool IsValidDynamicItem(int commandId)
{
return ((commandId - _baselistID) < connectionsCount); // here is the place to put the criteria to add a new command to the dynamic button
}
private void OnInvokedDynamicItem(object sender, EventArgs args)
{
DynamicItemMenuCommand invokedCommand = (DynamicItemMenuCommand)sender;
if (null != invokedCommand)
{
.....
}
}
private void OnBeforeQueryStatusDynamicItem(object sender, EventArgs args)
{
DynamicItemMenuCommand matchedCommand = (DynamicItemMenuCommand)sender;
bool isRootItem = (matchedCommand.MatchedCommandId == 0);
matchedCommand.Enabled = true;
matchedCommand.Visible = true;
int indexForDisplay = (isRootItem ? 0 : (matchedCommand.MatchedCommandId - _baselistID));
matchedCommand.Text = "Text for the command";
matchedCommand.MatchedCommandId = 0;
}
}
I had to review a lot of documentation since it was not very clear how the commands can be added on execution time. So I hope this save some time whoever has to implement anything similar.
The missing piece for me was figuring out how to control the addition of new items.
It took me some time to figure out that the matches predicate (the IsValidDynamicItem method in the sample) controls how many items get added - as long as it returns true, the OnBeforeQueryStatusDynamicItem gets invoked and can set the details (Enabled/Visible/Checked/Text etc.) of the match to be added to the menu.