I have a widget that is using an alarmmanager to make frequent updates (when the phone is awake). Since the update requires hitting a local arduino webserver the update is being done in a service.
Based on the results want to set a TransitionDrawable to one layer or the other. Is there a way I can tell which layer is currently displayed so I can tell which direction and if I should transition at all?
I don't think there is something like that. you can try drawable.getLevel() and see if it helps. the transition drawable implementation in my experience doesn't offer more than start and the reset method, so i wouldn't put much effort into it.
if getLevel doesn't work just handle that with a flag marking your state, anyway you have to manually run it and there can only be 2 drawables set right?
Related
I dont know this is the right place to ask, but since Autodesk redirects here on their 'get help' page, im trying anyway....
We have a couple of autodesk models that we display using their viewer. Also, we had a couple of 'presets' configured: camera positions based on XYZ of the camera and XYZ of the target the camera is looking at. So, when you push the preset, the camera position changes towards the XYZ and the target is set as well.
This worked fine - untill this weekend (23-04-2018): The positions are completely off... E.G. one of the presets did center the viewable area on a specific part of the model and now it seems the model is zoomed out 50 times and in another angle (we are using the perspective camera). I'm not sure what's the cause of this, but if i had to guess, it would be that the parsing of the source DWG is done again automatically and the center of the model as SVG shifted, and thus the stored XYZ coordinates are useless.
Obviously we can reinitialise the presets, but since i dont know what caused this, im unsure if thats just wasted time. Now the question: Does anyone know what is the cause of this and can we avoid it?
Ahh - ok, seems to be related to the version of the viewer - although im still unsure why it switched (there was no new version released afaik) manually specifying
<script src="https://developer.api.autodesk.com/modelderivative/v2/viewers/viewer3D.min.js?v=v4.1.0"></script>
fixed it.
There were indeed some changes that might have affected the scenes that "manipulates" with positioning (be it camera or component).
The scene I usually use to illustrate the component transformations: http://giro-watch.tk/ was "broke" when I updated to the latest Viewer version.
In case you refer to the Forge Viewer lib without specifying the version:
... src="https://.../v2/viewers/viewer3D.min.js?v=v4.1"></script>
as in this case, omitting ?v=v4.1,
you will get the latest version of it and since recently the Forge Viewer changed from v3 to v4, some breaking changes were expected.
However, between you and Autodesk server, might be a couple of services that caches this file and this is why you project might work fine even after the Forge Viewer was updated and just now the caches were cleaned/renewed.
This is why we recommend to always use versioning in production code.
I am making a game in Corona SDK in which I want to be able to save the player's high score to the device that they are using's disk, just so that it will stay saved even if the user restarts the app.
Problem is, everywhere I go online for help on this sort of thing I am told I should be using JSON, but I am not sure if there is a simpler way of doing things or even if JSON is the right approach.
Maybe try Introducing new preference storage features.
heres a neat thought that may work. make a new scene that contains the high score variable but dont erase the variable when exiting. then everytime they want to check their high score they just have to go to the scene.
option 2 - this one is a bit more tricky and im not exactly sure if you need permissions aka administrator rights (and if you are submitting your app on googleplay you may need to ask for permission. so review the rules before doing it), write a batch file that copies the highscore into a new file.
option 1 is better because you are not necessarily adding anything.
I'm pretty new to HTML5, and want to know if this is possible.
I want to be able to create a canvas in which I can load an image in it, and then draw on it for other people to see, and allow them to make changes to it as well.
It doesn't have to be super complicated with lots of different tools, just basic stuff. I just want to be able to change the image every now and again.
Is this possible, and if so, can someone point me towards a tutorial of some sort?
Do you already know how to do non-image collaboration?
The way you do collaborative editing of any medium is pretty much the same.
The main difference between one medium and the next is the content of the updates (DOM elements vs. paint events). The other big thing you'll run into has nothing to do with the medium, but whether you want to use AJAX or WebSockets or what have you - this is a question more about the method through which you accomplish the collaboration.
The essential concept is (from the user's perspective):
Submit my own changes
Check periodically via AJAX to see if anyone else has made changes, or use WebSockets/long polling to be notified immediately of changes from others
Update each person's view with the changes from other users
Figure out a way to resolve conflicts if two changes are incompatible, if this applies to your problem
Provide some way for users to "undo" things
Not to blow my own horn, but last year I wrote a collaborative scratch paper/brainstorming app called cortex, and I blogged about each commit and how I figured out how to do the realtime collaboration. I did it in Rails using an AJAX approach, but the concepts I used for real-time collaboration are applicable to most any app that wants to take a similar approach. This post includes a video simulating two users collaborating on the same page, and how soon/how often updates from one client are shown on the other client browswer.
cortex isn't the prettiest or most advanced thing in the world, but I think it's a good intro app to get the concepts down. It may not even be the best designed (it was my first collaboration app), but I use it nearly every day and it seems to work well enough.
I'm experimenting with P2P on Flash, and I've come across a little hurdle that I'd like to clarify before moving forward. The technology itself (Flash) doesn't matter for this problem, as I think this problem occurs in other languages.
I'm trying to create a document that can be edited "live" by multiple people. Just like Google Docs pretty much. But I'm wondering, how would you suggest synchronizing everyone's text? I mean, should I message everyone with all the text in the text field every time someone makes a change? That seems very inefficient.
I'm thinking there has to be a design pattern that I can learn and implement, but I'm not sure where to start.
Optimally, the application should send the connected clients only the changes that have occurred to the document, and have some sort of buffer or error correction that can be used for retrieving earlier changes that may have been missed. Is there any established design pattern that deals with this type of issue?
Thanks,
Sandro
I think your "Optimally" solution is actually the one you should go for.
each textfield has a model, the model has a history (a FILO storing last, let's say, 10 values).
every time you edit that textfield you push the whole text into the model and send the delta to other connected clients.
as other clients receive the data they just pick the last value from the model and merge it to the received data.
you can refine the mechanism by putting an idle timer in the middle: as a user types something in the textfield you flag that model as "toBeSentThroughTheNet" and you start a timer. as the timer "ticks" (TimerEvent.TIMER) you stop it, collect the flagged data and send it to other clients. just remember to reset the timer everytime the user is actually typing (a semplification coul be keydown = reset, keyup = start).
one more optimization could be send the data packed in a compressed bytearray, but this requires you write your own protocol and may be not so an easy and quick path :)
If the requirement is that everyone can edit the document at the same time and the changes should be propagated to everyone and no changes should be lost, then it is a non-trivial problem. There are few different approaches out there, but one that is quite robust is Operational Transformation. This is the same algorithm that Google Docs uses for collaborative editing.
Understanding and Applying Operational Transformation and the attendant hacker news discussion are probably other good places to start.
The Wave Protocol was released as open source so you can take a look on how it is implemented.
You could of course forgo the tricky synchronization and just allow people to take turns and only one person can edit the document at a time and this person just pushes the changes to the remainder of the group.
For a major school project I am implementing a real-time collaborative editor. For a little background, basically what this means is that two(or more) users can type into a document at the same time, and their changes are automatically propagated to one another (similar to Etherpad).
Now my problem is as follows:
I want to be able to detect what changes a user carried out onto an HTML textfield. They could:
Insert a character
Delete a character
Paste a string of characters
Cut a string of characters
I want to be able to detect which of these changes happened and then notify other clients similar to "insert character 'c' at position 2" etc.
Anyway I was hoping to get some advice on how I would go about implementing the detection of these changes?
My first attempt was to consider the carot position before and after a change occurred, but this failed miserably.
For my second attempt I was thinking about doing a diff on the entire contents of the textfields old and new value. Am I missing anything obvious with this solution? Is there something simpler?
It is a really hard work make this working today, for several reasons, but
maybe you will need to restrict only to some browsers. read: https://developer.mozilla.org/en/XUL/Attribute/oninput the alternative to "oninput" is listen to all input events (keyboard, mouse, dragdrop) I suggest to use "oninput"
html is not perfect... even html5. input and textareas supports only single-range
selections. you can solve this using designmode/contenteditable instead of
textareas/textfield
detecting offsets of what changed is a hard work: read
-- https://developer.mozilla.org/en/Document_Object_Model_%28DOM%29/window.getSelection
-- http://www.quirksmode.org/dom/range_intro.html -- http://msdn.microsoft.com/en-us/library/ms535869%28v=VS.85%29.aspx -- http://msdn.microsoft.com/en-us/library/ms535872%28v=VS.85%29.aspx
you may need a "diff" algorithm written in javascript! http://ejohn.org/projects/javascript-diff-algorithm/
one personal note: detecting words, characters changes may be totally non-sense and not useful, detect instead paragraphs changes, or in case of an excel-like worksheet, the single cell
I hope this helps
feel free to correct my English!
My pseudocode/written out response would be (if I understand your question exactly) to use jQuery to detect keyup events and then save the input to the server via ajax, then also take the response and post it back to the input. This isn't very efficient, but basically the idea is that you're constantly posting and checking what else has been posted. If you want to see what someone else is doing in real time, you can ping the server every second or so and update with the response.
All of this of course can be optimized, but it still is kind of taxing for a server. You could also see if you can implement Google Topeka Wave for your project, or get in touch with Google Topeka to see how they do it :)