I have a Eclipse plugin that uses a view which extends ViewPart. ViewPart has a saveState method which requires an IMemento.
I added my code to saveState and the corresponding init method and it works. Unfortunately, saveState is only called if the entire workspace is shutting down. My view is not of such great importance that I can expect it to be opened the entire time. Hence, it would be cool if saveState would be called on view closure.
I found a view-part listener as mean to react on view closure, but what I do not get is where the IMemento comes from. Where do I get the memento object that is used on workspace closure? Or where do I have to store my own memento object to make the view part use it in the init method if the view is (re)opened?
#Override
public void saveState(IMemento memento) {
super.saveState(memento);
memento = memento.createChild(MEMENTO_GUI_STATE);
memento.putBoolean(MEMENTO_IS_FLAT, !isHierarchicalModeActive());
memento.putBoolean(MEMENTO_IS_CATEGORY_MODE_ACTIVE, comboViewer.isVisible());
}
This is my saveState - can I tell my view somehow tell to call it every time the view closes?
Take a look at this question in the Eclipse FAQ:
Storing view state is done in two commons ways, depending on whether
you want to store settings between workbench sessions or across
invocations of your view. The first of these facilities is found
directly on IViewPart. When the workbench is shut down, the method
saveState is called on all open views.
Another mechanism for persisting view state is the JFace
IDialogSettings facility. The advantage of dialog settings over the
view save/init mechanism is that you can control when settings are
persisted. The saveState method is called only if your view is open
when the workbench shuts down, so it is not useful for storing view
state when the view is closed by the user. Dialog settings, on the
other hand, can be changed and persisted whenever you want.
Go to this other question or to the Eclipse documentation itself for the settings mechanism.
Well this could be "a bit" ugly but nothing else came to my mind: store memento variable as a field variable, initialize it in your init(IViewSite site, IMemento memento) method, override dispose() and call saveState(IMemento memento) explicitely.
You can read and write your own XMLMemento from your org.eclipse.core.runtime.Plugin.getStateLocation() at any time you want. As #BelaViser mentioned, you could write your file in your IViewPart#dispose() method and read it in your view constructor.
Related
In a Dolphin smalltalk treeview I'd like to use a custom icon, depending on the state of the item displayed, (differente state, different icon)
How can I do that ?
I cannot really understand how to use a "my" icon.
I've create a class "connection", with an instance variable "connected"
and two class methods "connectedIcon and unconnectedIcon that returns icon images.
Then an instance function "icon" that returns one or the other image based on the connection state.
I can add instances of this class to a tree view and see the name of the connections.
But how to show my Icons ?
I tried to sustitute the getImageBlock of my presenter view with the following expression [:obj | obj icon] but it doesn't work.
(nothing seems to happen).
this is made in my presenter initialize :
initialize
super initialize.
treePresenter view getImageBlock: [:obj | obj icon]
what's wrong with it ?
best regards
Maurizio
When you are editing a TreeView, one of the properties is getImageBlock. By default it is not really a block but another object that understands the message #'value:' (the class IconicListAbstract). You can replace this property with a code block (or other object that understands #'value:') and answer the image you want displayed.
In Microsoft Windows, icons are typically stored in a DLL. You should be able to use an icon explorer or editing tool to see the icons in a dll. For example, get IconExplorer from http://www.mitec.cz/iconex.html and try opening DolphinDR7.dll. Do the icons and numbers match what you see when you return a number in your application?
To determine (or override) the resource library used, see SessionManager>>#'defaultResLibPath'.
Typically, the getImageBlock is set using the property editor in the GUI editor, but setting it through code can work as well.
Wonderful Dolphin Smalltalk!
I had two problems
1) how and where to modify the getImageBlock method of my Treepresenter.
2) where to put the icons ad how to get the imageindex of each icon.
This is the solution :
1) it's not needed.
The treeview sends an #iconImageIndex" message to my model
this is handled by the default method (in the Object class) that send to my object the message #icon
and to the result of this message (an icon) the message #iconIndex.
This message is understood from the icon that answers with its own iconIndex.
So the only method I need to impement is #icon in my class Connection
that I implemented as follows:
icon
opened ifTrue: [^Connection connectedIcon] ifFalse: [^Connection unconnectedIcon]
In the class itself the two icons are imported in the image by evaluating the createIconMethod,
as explained in the blog article 'Beauty with less Beast'.
So my problems are solved.
Thanks to all.
Maurizio.
My application has deep navigational chains of 8+ screens deep (Wizard-style). When i'm editing a View Controller, and i want to make a quick visual change and re-test, As a tester, I have to go through the full flow to end up where I was before recompiling, in the same Data state. Is there a way that Xcode can somehow preserve the application state, and re-run the same view controller?
If there was an automated way to detect the last launched screen, and re-display it after the recompile, that would save a lot of developers a lot of time.
I realize something like this can be built custom. Something like:
IF A Certain Debug Flag is ON:
- Retrieve from NSUserDefaults the Class Name of the last controller used, and redisplay it.
The problem with this is: Data State and Navigation State will not be preserved. Also, all other object state which invokes and depends on your controller will not be included. That's why I need a more universal solution.
IF A Certain Debug Flag is ON: - Retrieve from NSUserDefaults the Class Name of the last controller used, and redisplay it.
The problem with this is: Data State and Navigation State will not be preserved.
But this is exactly the problem that the built-in state saving and restoration mechanism is intended to solve, is it not?
https://developer.apple.com/library/ios/featuredarticles/ViewControllerPGforiPhoneOS/PreservingandRestoringState.html
I recommend you use a User Interface target and then create an XCTestCase that works on your view controller and exercise it. Use the new record button in Xcode 7 to get you started with the test case. Familiarize yourself with some of the new queries it uses for some of the dynamic information you may be creating.
Another option would be to inject your test case's UI state into the application delegate in the setup function of an XCTestCase. Then it will need custom logic to navigate to the correct view controller. Then your test case could focus on just that ViewController once the Application delegate has navigated to it.
Of course you can use the debugger and breakpoints in the Test Case and your View Controller while UI Testing. By "scripting" this you do significantly less manual clicking on a device to test a ViewCOntroller
Also you've now got a Test! Hopefully worth something to you down the road when you change something
I've noticed the following error popping up in the console when running my app on iOS 9 when using a storyboard. I'm using xCode7. Is this something I need to be concerned about?
-[UIApplication _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion:] ** unhandled action -> <FBSSceneSnapshotAction: 0x176bfb20> {
handler = remote;
info = <BSSettings: 0x176a5d90> {
(1) = 5;
};
}
There is nothing wrong with your code. This is a logging message internal to Apple, and you should file a radar about it.
There are two hints that show that this is probably Apple's code:
The underscore leading the method name _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion is a convention indicating that the method is private/internal to the class that it's declared in. (See this comment.)
It's reasonable to guess that the two letter prefix in FBSSceneSnapshotAction is shorthand for FrontBoard, which according to Rene Ritchie in "iOS 9 wish-list: Guest Mode" is part of the whole family of software related to launching apps:
With iOS 8, Apple refactored its system manager, SpringBoard, into several smaller, more focused components. In addition to BackBoard, which was already spun off to handle background tasks, they added Frontboard for foreground tasks. They also added PreBoard to handle the Lock screen under secure, encrypted conditions. [...]
I have no idea what the BS prefix in BSSettings is for, but
BS is shorthand for BackBoard Settings, and an analysis of this log message would indicate that it's not anything you did, and you should file a radar with steps to reproduce the logging message.
If you want to try and grab a stack trace, you can implement the category linked to here. Some would argue that overriding private API is a bad idea, but in this case a temporary injection to grab a stack trace can't be too harmful.
EDIT:
But, we still want to know what this action is. So I put a breakpoint on -[UIApplication _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion] and started printing out register values and found a class called FBSceneImpl which had a whole bunch of information about my application:
We are able to find out which private method is called next (stored in the program counter, instruction pointer, register 15.)
I tried finding the un-handled FBSceneSnapshotAction referenced in the log, but no dice. Then, I subclassed UIApplication, and overrode _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion. Now I was able to get at the action directly, but still, we don't know what it is.
Then, I looked at the FBSceneSnapshotAction again. Turns out it has a superclass called BSAction.
Then I wrote a tool similar to RuntimeBrowser and looked up all of the subclasses of BSAction. It turns out that there's quite a list of them:
The two method names we have (one from the log and one from the program counter on the devices) indicate that these actions are used under the hood for passing actions around the system.
Some actions are probably sent up to the app delegate's callbacks, while others are handled internally.
What's happening here is that there is an action that wasn't handled correctly and the system is noting it. We weren't supposed to see it, apparently.
AFAIK, the info above is related to iOS during snapshot the screen (i suppose for double click home multitask related behaviour).I deeply investigated my application and seems that it does not get any side behaviours. You can safely ignore it, for now.
You can use the following gist simple category to test yourself against the calls to the above function:
I have figured it out, it will happen when you have IBAction method declared in .h or .m file but you have not bind it to any control.
.m example:
- (IBAction)click:(id)sender{
}
but not assigned this method to any control in storyboard.
haven't find out why it happens in my app, but at least you can catch the exception, if you want to keep this from popping up in your log pane. It's not a solution, but it might give you more insight why it is happing by inspecting any of the arguments that are passed in the catch.
swift 2 version:
import UIKit
extension UIApplication {
func _handleNonLaunchSpecificActions(arg1: AnyObject, forScene arg2: AnyObject, withTransitionContext arg3: AnyObject, completion completionHandler: () -> Void) {
//whatever you want to do in this catch
print("handleNonLaunchSpecificActions catched")
}
}
I have some NSManagedObject subclass in my app, and I'm trying to understand when and how to save changes.
I will try to explain myself, for example class A is NSManagedObject subclass.
During app life cycle I do:
App launched
...
Create an instance of class A
...
Change some properties of A instance
...
App go to background
...
App becomes active again
...
Change some more properties of A instance
...
App terminates
When do I need to call [context save:] ??
Do I call it after every change in A instance? Or maybe I call it only when app go to background?
Should I call it after creation or deletion of any A instance?
A nice approach is place UIManagedDocument in your AppDelegate. Then you can call [context save] whenever some change occurs in the app (like a crash). The order I like to follow is something like:
Create UIManagedDocument object (in application did load or wherever)
and assign it to a property
Setup the document (check whether it exist on disk or is already open, etc.. and respond accordingly)
Pass the UIManagedObjectContext to the initial UIViewController in your app (from there you can pass the context to other view controllers)
UIManaged document will save the context for you.
Take a look at the UIManagedDocument documentation to configure persistent store options (you send an NSDictionary of options to your UIManagedDocument instance, see the first example through the link below).
UIManagedDocument documentation:
http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIManagedDocument_Class/Reference/Reference.html
Also see the CoreData lecture and demo (lectures 13 and 14) of the iPhone and iPad application development course with Paul Hegarty available free on iTunesU (Fall 2011).
The data will not be saved to the persistent store until you call save. So, it depends on what you want in your app. If you want it to be able to recover the last value it ever had, then you should save after each modification.
Easy change is to just save after making modifications.
You could do something a bit more fancy, like only save after some set amount of time, so many changes are grouped together... and catch any event that will put your app in the background and then save...
But, that's what UIManagedDocument does automatically for you, so you could just use that instead.
Depending on the amount of changes that you make and the volume of data that needs to be saved with each change, yo can choose to save a little or a lot. If you are just saving a string or a number or a bool, then go ahead and call save: on your context as soon as the changes were made.
If it is a lot of data, you may want to coalasce your changes and then save it on a background queue so that you are not blocking the main queue. This way you are not waiting to go to the background to perform your saves.
Tim
I have a program that is getting pretty big and it is a pain to find everything through all the functions and classes.
I am trying to break it up into other files based on their method.
Some of these functions have calls to others in the main class. I changed most my functions from private to public to access this. I had problems calling certain code created windows so importing mainwindow helped that.
My last problem is editing the mainwindow ui from one of the module files. I want to make sure im on the right page before i continue breaking it up. My only guess is that anything they updates the ui should be left on the main class.
Thanks
The only code in your form class should be code that talks to other classes and updates the UI based on data from other classes.
Depending on your application, the form class might handle change events from other classes to update the UI or pass user input to other classes in Change or Click events.
A couple options:
Use callbacks into the your main window.
Create events for when you need the form updated. Your program logic raises the events, and your main window class can consume them.