I am having some doubts whether I understand correctly the concept of static component or not.
I am designing an experiment where I am presenting images for certain durations and once an image is gone the participant will have to submit a response.
I am using the builder for this and usually at the end I go on the coder view to make some minor alterations (randomise inter-trial durations etc)
So in the builder, I start a loop where my first routine has an ISI component for 0.5 seconds, then I add an image ad 0.5 seconds, a second routine in the loop records the key response.
What I want to do, in order to avoid lag, is to load the image during the ISI and then display it after the 0.5 seconds have passed. I am ok with the condition file and how to use parameters as variables. So in the Image entry I use $image (as declared in my excel file), I also declare that I want this image to be set "during trial:ISI". Does this do what I have in mind? Load the image during ISI and flip it once ISI finishes?
Secondly, do you think it will be more efficient to have the ISI and the image in different routines inside the same loop?
If you have any other suggestions on how it can be done in a more efficient way please let me know.
Thank you.
(1) Yes, this is the correct way to use the ISI to pre-load an image.
(2) No, there is no need to split across different routines.
(3) You should avoid going "on the coder view to make some minor alterations". Once you make changes there, the Builder view can't be utilised any more. It is very likely that you can achieve what you want by putting code within a Code Component in the Builder view, so you don't have to abandon the advantages of the graphical interface.
Related
My team and I have to make a license plate scanning app as a school project. With that, we have comments and pictures which can be added to cargo. Whenever the user scans a plate they also get the chance to change the checked info in case of a mistake. The problem is that whenever we delete data from the scanned plate it doesn't show on the screen that it has been deleted until we go to another screen. The same goes for the lazy column which we use for inserting new instances of comments and pictures. The data doesn't show on screen until we turn our screen or go back to another screen. private val pictureList = mutableListOf() is what we use for the pictures and for the text we use var countryCode by remember { mutableStateOf(CountryCodeText) }
var licenseNumber by remember { mutableStateOf(LicenseNumberText) }. pictureList is a global variable and the other ones are local variables which use global variables in the mutableStateOf. How can we make sure that the UI updates whenever the data changes? In advance I want to say thanks for the help! (Code is written in Kotlin and jetpack compose)
Just replace the mutableListOf() with a mutableStateListOf(...), and prefer to keep all the state logic confined to a ViewModel. The viewmodel should preferably be only one for the entire app, and the entire app should have only one activity.
The viewmodel should act as a single source of truth for the entire activity's UI state, while also handling all the updates to the UI efficiently.
The #Composables should only be incharge of displaying the state, and sending events to the viewmodel to update the state, for example, an onClick event may be sent up to the viewmodel by a button too trigger a state change in another part of the app.
Take this codelab to learn all about state in Compose (Well, not all, really, but good starter).
Also, changing screens destroys all the #Composables of the current screen, and so when you ce back there, all the #Composables are re-created, and the correct data is fetched. If you wish to trigger "recompositions" upon changing a variable, you must ensure that the concerned variable is a state-holder, i.e., initialized with one of the pre-built state initializers, like mutableStateOf(), or mutableStateMapOf, etc.
We usually have a mutableState*Of format for determining whether a pre-built state initializer is available. The most common ones are covered, obviously, but if not, you'll need to create a new type of initializer yourself, and if that is not something you know how to do, currently, you can just go about checking whether the type of data you wish to store is Immutable. If so, you can just wrap it in a mutableStateOf<DataType>() call, and it will trigger the recompositions. Know that this is not as efficient as pre-built initializers, but definitely gets the job done.
Also, I suggest you take the compose-pathway to get the basics down. It covers everything ranging from creating a simple UI using basic pre-built Layouts to creating a complex animation-driven application using custom Layouts.
So, definitely a lot to take it, but I hope you get there.
Happy composing,
Is there an example of the resize function for dropzone.js? I don't really understand how it works, it says:
"Resize is the function that gets called to create the resize information. It gets the file as first parameter and must return an object with srcX, srcY, srcWidth and srcHeight and the same for trg*. Those values are going to be used by ctx.drawImage()."
But I don't really get how to use it. So far I'm resizing the images on server-side, but I'd like to do it client-side and I think this might help. Any other solutions using dropzone.js if not this one?
I believe the built-in resize function in dropzoneJS is what is used to create the thumbnail, not resize the photo client-side, per se. There might be some way you could leverage it by setting the thumbnail dimensions to what you want to save to the server, and overwriting the file being saved with the thumbnail, but I'd have to hack about for a spell to offer you any code suggestions for that.
I am writing an app in which I have two UITextFields...
Starting Text
Destination Text
Now once I place values and hit the search or whatever function I want to call, I Want to reuse these values. The app should record and save these values as cache. And should show them when typing or upon a button click. Is that possible to show them just like Dictionary words show up or Which is more preferable tableView or PickerView? If there is any other please let me know.
Definitely use a UITableView. A UIPicherView is used modally most of the time and not for optional suggestions.
Table view is used in Safari, and a lots of other apps:
As for how to cache the data, you have lots of options. It also depends on how much data you expect.
One easy way would be to simply use NSArray. You can very easily write an NSArray to disk in a plist file and read it back when you need it.
Or you could use Core Data, if you expect lots of data and still want high performance. It will be a lot more difficult though to get used to that API if you've never tried it before. Basically you'll need a simple model with one entity called something like SearchEntry that has a single property text. Then you keep adding new instances to your managed object context and can easily filter the existing values.
Consider the following, I have paragraph data being sent to a view which needs to be placed over a background image, which has at the top and the bottom, fixed elements (fig1)
Fig1.
My thought was to split this into 4 labels (Fig1.example2) my question here is how I can get the text to flow through labels 1 - 4 given that label 1,2 & 3 ar of fixed height. I assumed here that label 3 should be populated prior to 4 hence the layout in the attached diagram.
Can someone suggest the best way of doing this with maybe an example?
Thanks
Wish I could help more, but I think I can at least point you in the right direction.
First, your idea seems very possible, but would involve lots of calculations of text size that would be ugly and might not produce ideal results. The way I see it working is a binary search of testing portions of your string with sizeWithFont: until you can get the best guess for what the label will fit into that size and still look "right". Then you have to actually break up the string and track it in pieces... just seems wrong.
In iOS 6 (unfortunately doesn't apply to you right now but I'll post it as a potential benefit to others), you could probably use one UILabel and an NSAttributed string. There would be a couple of options to go with here, (I haven't done it so I'm not sure which would be the best) but it seems that if you could format the page with html, you can initialize the attributed string that way.
From the docs:
You can create an attributed string from HTML data using the initialization methods initWithHTML:documentAttributes: and initWithHTML:baseURL:documentAttributes:. The methods return text attributes defined by the HTML as the attributes of the string. They return document-level attributes defined by the HTML, such as paper and margin sizes, by reference to an NSDictionary object, as described in “RTF Files and Attributed Strings.” The methods translate HTML as well as possible into structures of the Cocoa text system, but the Application Kit does not provide complete, true rendering of arbitrary HTML.
An alternative here would be to just use the available attributes, setting line indents and such according to the image size. I haven't worked with attributed strings at this level, so I the best reference would be the developer videos and the programming guide for NSAttributedString. https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/AttributedStrings/AttributedStrings.html#//apple_ref/doc/uid/10000036-BBCCGDBG
For lesser versions of iOS, you'd probably be better off becoming familiar with CoreText. In the end you'll be rewarded with a better looking result, reusability/flexibility, the list goes on. For that, I would start with the CoreText programming guide: https://developer.apple.com/library/mac/#documentation/StringsTextFonts/Conceptual/CoreText_Programming/Introduction/Introduction.html
Maybe someone else can provide some sample code, but I think just looking through the docs will give you less of a headache than trying to calculate 4 labels like that.
EDIT:
I changed the link for CoreText
You have to go with CoreText: create your AttributedString and a CTFramesetter with it.
Then you can get a CTFrame for each of your textboxes and draw it in your graphics context.
https://developer.apple.com/library/mac/#documentation/Carbon/Reference/CTFramesetterRef/Reference/reference.html#//apple_ref/doc/uid/TP40005105
You can also use a UIWebView
I'm using a gtk.Image widget to display a picture in a gtk window. I can set the image to be displayed before I call window.main(), but after I've done that the image won't change any more. Basically:
import pygtk
pygtk.require('2.0')
import gtk
(...)
window= Window()
window.canvas= gtk.Image()
window.window.add(sprite.window.canvas)
window.canvas.show()
window.canvas.set_from_file("pic1.gif")
window.main()
window.canvas.set_from_file("pic2.gif")
pic1.gif will be displayed. Is there a proper way of changing the image (I don't care if I have to use a widget other than gtk.Image)? All I can think of is destroying the window and creating a new one.
Edit:
I realized my mistake... I called window.main() for every window and any window's destroy event called gtk.main_quit(). Had to make slight adjustments, but it works now. Even after calling window.main() :)
As Rawing hasn't yet accepted his own answer, I'll post it to get this off the top of the unanswered questions page, and to help out anyone skimming this from a search engine clickthrough by providing a comprehensive answer. (Rawing, feel free to post your answer yourself, all the same.)
In your code, you're declaring window as Window(), as opposed to gtk.Window. If you're building in one window, you should not need to do this every time. Create the window once, add what you need to it. If you need additional windows, declare them separately in this module, and call them from code (instead of from main).
Furthermore, don't name your objects with a "window." at the beginning...that just gets overly confusing. Give it a simple name, add it where you need it. Python will do the rest.
A cleaned up version of your code above would probably look like this:
window = gtk.Window()
#You may need additional arguments above, such as to make it top level.
canvas = gtk.Image()
window.add(canvas)
canvas.show()
canvas.set_from_file("pic1.gif")
Now, just change the image in an event or another "def", like this:
def ChangePicture():
canvas.set_from_file("pic2.gif")
Canvas should update the picture automatically.