Office Hours — Today, June 7

Thursday, June 2

Mark M.
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Mark M.
turned on guest access
Kathy
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Mark M.
howdy, Kathy!
Kathy
Hi Mark
Mark M.
how can I help you today?
fitz
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Kathy
I am working on some checkboxes and would like circles instead of a checkmark. I saw a reference to btn_circle but have not been able to find the xml files. Do you know where I might find them?
fitz
Mark - I just got pulled into a meeting so till next time :)
Mark M.
let me poke around for a moment -- hold on
Jun 7
7:40 PM
fitz
has left the room
Mark M.
Kathy: it is in $ANDROID_SDK/platforms/$VERSION/data/res/drawable
where $ANDROID_SDK is wherever you installed the SDK
and $VERSION is some Android version subdirectory (e.g., android-8)
it is a StateListDrawable
Kathy
I will go look for it now
Mark M.
pointing to a series of PNG files for the different states
Kathy
okay, i found btn_circle, where are the other files it references?
Mark M.
different versions exist in the different density directories
e.g., drawable-hdpi
Kathy
ok, thanks, I found them.
Mark M.
since device manufacturers have a tendency to tinker with those sorts of resources, you may want to copy them into equivalent directories in your project
then refer to your local copy as needed
7:45 PM
Kathy
Good advice, I will do that.
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I have another question about sliders that I have seen in iphone apps that let you say like how dark or light a photo is.  Are there examples or
tutorials to do something like that in Android?
Mark M.
in terms of the "slider", usually people use SeekBar
Kathy
ok, I am trying to find an example of one right now so I know what you are talking about.
Mark M.
in terms of adjusting the brightness of the photo, if you are really trying to do the photo manipulation on-device, you probably need to fuss with settings on Bitmap, but I've never done that
yeah, I don't use SeekBar much in my books
Kathy
I am a serious photographer and have wanted to do a photo app and have been realizing that it is far more difficult than I first realized and I have a bit of a learning curve.
Mark M.
yes, trying to do photo manipulation on a mobile device won't be trivial
Kathy
A lot of the iphone photo apps use these sliders for adustments.
7:50 PM
Kathy
I am just beginning to realize what is involved in doing a photo app, do you have any suggestions on where I might look to educate myself?
Mark M.
I know very little about photo manipulation
haven't a clue where you'd go learn
sorry
Kathy
I seem to need some basic computer grahics understanding that I am missing. Any ideas on where I could get started on just that?
Mark M.
well, Android doesn't have much in the way of built-in APIs for that
Kathy
That is what I am discovering.
Mark M.
so your choices are either to find a Java image processing library...
...or learn C/C++ and integrate something like the ImageMagick library via NDK and JNI
Kathy
I have heard mention of OpenGL, would I be able to use that?
Mark M.
OpenGL is a 3D graphics engine
used mostly for gaming
Kathy
Probably more than what I will need.
Mark M.
not sure how applicable it is to photo manipulation, in large part because I know very little about photo manipulation
if what you were trying to find was what a SeekBar looks like, that's one there
7:55 PM
Kathy
The seek bar looks like it will work for what I want. Thank you.
Mark M.
users slide the thumb, and you get a value from 0 to whatever maximum you set
Kathy
I have another sort of general question. During the google question they mentioned using a dashboard to navigate in apps. Are there any example of code I could look at?
Mark M.
well, the Google I|O app itself uses a dashboard
you can download that on the Market
and the code is available
Roman Nurik (a Googler) also created a custom layout manager for this: https://gist.github.com/882650
that too is part of the Google I|O app
personally, I think dashboards are an OK pattern but not applicable to all apps
Kathy
I was wondering that myself. At the conference they were recommending it, but I am not sure how I feel about it.
8:00 PM
Mark M.
it's certainly an option for apps that have multiple avenues for accessing information, with none standing out as being clearly dominant
but, for example, if I click on a "Contacts" icon, I certainly expect to be presented with a list of contacts
not a dashboard, on which I have to tap something else to get to the list of contacts
so, an app in support of a conference, like the Google I|O app, it may make sense
Kathy
it seems like at times it can become bulky
Mark M.
schedule vs. session listing vs. map of rooms -- none are obviously the entry point
right
Kathy
I am in the middle of designing an app now where I was considering a dashboard, but I think tabs might be better.
Mark M.
that's certainly a possibility
the tradeoff is clicks vs. space
tabs give you both some content and access to a few other areas of the app
but you lose the space for the tabs themselves
if there are only a couple of options, an action bar might be better (if nothing else, smaller and fits better with Honeycomb)
Kathy
I guess I have to be careful about the number of tabls. Right now I have four. I guess it is possible to drill down from the tabs also.
8:05 PM
Mark M.
be careful, though
tabs in Android are not designed to be used for internal navigation
i.e., you click on X and something new opens in the same tab
it's possible but difficult
I'm not a big fan of that pattern
at least on phone-sized screens
Kathy
Well, I will take all this into consideration. That app is still in the design phase, so can be easily changed.
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Thank you for all of your help.  I don't have any more questions for now, but I will be working on my app this week so I will be coming up with more.
Mark M.
ok, next chat will be Thursday, 10am Eastern
Kathy
I will put it on my calendar.
8:20 PM
Kathy
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8:30 PM
Mark M.
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Thursday, June 2

 

Office Hours

People in this transcript

  • fitz
  • Kathy
  • Mark Murphy

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