I want to develop an android application, but i dont want to use the default controls(buttons, checkboxes, radio buttons, etc.,). Is there any way to customize those controls to make it appear nicer. If so some tutorial or guide will help me a lot. Thanks....
If you want to create completely new UI elements, you should read the developer guide topic on creating custom components/views.
If, on the other hand, you simply want to change the appearance of existing UI elements, below is a non-exhaustive list of things you'll need to do. This assumes you're familiar with the Android resources framework and layout system.
First, see how these are implemented in the Android source code (AOSP, GitHub's mirror). All of the code you're interested in is in the frameworks/base.git project (quick links: resources, Java sources)
For each type of UI element, create Nine Patch PNG drawables for each of the UI states (default, disabled, pressed, focused, etc.) and for each relevant density (e.g. medium, high , and extra-high densities). These PNGs should be in your res/drawable-mdpi/, res/drawable-hdpi/, and res/drawable-xhdpi/ directories.
For each type of UI element, create a state list XML drawable (<selector>), which will be in your res/drawable/ directory. The state list drawable for the default Android push button can be found here.
Set your button/textbox/etc.'s android:background attribute to the state list drawable name. For example, the attribute value should be #drawable/mybutton if your state list drawable is res/drawable/mybutton.xml. Note: You can use themes to reduce redundancy (i.e. keep them DRY) in your XML files.
Related
I have an Android app that uses a lot of XML drawables (shapes, layer lists, and state list), and I want to port this app to Windows Phone 8. Is there an equivalent to XML drawables (specifically the types I list above) in Windows Phone 8?
For layer lists and state list i think the equivalent is VisualStates but they are not so similar. Define different visual states for a control, You can find many different examples to VisualState's here inside a VisualState you gave different properties different values (such as different Image to background of a button when pressed) or define animations.
For shapes there are classes that you can define in your xaml file. If you want to define a gradient should look at brushes.
Im searching for an android gui-library with more components i could use in my app.
Example:
A microcontroller sends the rpm of a motor (via bluetooth) to my smartphone.
And i want to use my smartphone in order to show the received rpm in progressbar-like element.
But the normal progressbar looks ugly, and i would have to progressbar.setClickable(false); .
As i said before
Im searching a library with more gui-elements(optional: i could modify, customize the outward appearance on my own)
Do anybody of you know about such a library ?
Thanks so far.
If you're just concerned about the external appearance of your GUI elements, I don't think there's any support for different UI elements than the ones provided. However, have you looked into a universal Theme and style for your application?
Here are some excerpts from that document:
A style is a collection of properties that specify the look and format
for a View or window. A style can specify properties such as height,
padding, font color, font size, background color, and much more. A
style is defined in an XML resource that is separate from the XML that
specifies the layout.
A theme is a style applied to an entire Activity or application,
rather than an individual View (as in the example above). When a style
is applied as a theme, every View in the Activity or application will
apply each style property that it supports. For example, you can apply
the same CodeFont style as a theme for an Activity and then all text
inside that Activity will have green monospace font.
Here are some resources which talk about themes:
Mobile Orchard Article
Android Engineer Article
Let me know if that's what you wanted. Themes give you almost infinite possibilities to modify outwards appearance.
This is a question for Android developers but it is not a programming-related question as it affects nothing but the developer.
What conventions are the most commonly used when naming various resources like colors, drawables and strings and etc?
I have no doubts naming my layouts activity_main or layout_secondary. However, I have always doubts when naming resources mentioned previously. I never know whether I should name these resources after their use or the content. For example:
Color: dark_blue vs text_highlighted
Drawable: blue_gradient vs top_bar_background
String: welcome_to_app vs first_time_prompt
Is there any community-created resource for good practice?
Naming is pretty much personal preference. The name is perfect as long as the name indicates what the functionality of the defined thing is. Also you and any other developer using these definitions should know how what the names mean and which definition to choose. Quite easy if you are consistent with names throughout the project.
For example dark_blue is obviously a blue color while text_highlighted is the color of highlighted text. The name you should use depends on what you need: if you want to classify colors by their name take the first, if you like to abstract from the actual color take the second. For general layouts using text_highlighted will often make more sense since the actual color does not matter and the functionality (text highlight vs text regular etc.) is more important. In this example choosing between text_highlighted and text_regular is a lot more obvious than choosing between color_light_blue and color_dark_blue although they could refer to the same color. The name can help prevent errors.
Android uses prefixes for names in [android.R.drawable]
(http://developer.android.com/reference/android/R.drawable.html) for example:
btn_ for button graphics
ic_ for icon graphics
ic_menu_ for menu icons
ic_dialog_ for dialog icons
stat_ for status icons
The schema is certainly not perfect but the advantage of using prefixes that start with the most generic classification is that you can use code completion to search for specific items step by step. So color_blue_dark could be better than dark_blue_color, at least if you consider the color classification more important than the dark / light classification. The same applies to first_time_prompt. If you have a lot of prompts it would make sense to name them prompt_first_time, promt_other_time, ... If they can be classified by an activity for example that could be used as super category: mainactivity_prompt_*, secondactivity_prompt_* so you know where they belong to.
Android SDK will be a good place to start for the good practices. You can open up any sample code in the SDK and go through the code and see the variable names.
I usually name assets like colors and pictures for their content, but I will name a style or multiple state drawable for it's function.
for example:
button_On.png; button_Off.png; button.xml
That way if I want to use the same resource in multiple places it does not get confusing.
For example using a color as a text color in one style file and a background in another style file.
I'm looking at how to give an app that I develop and deploy it's own look and feel. So I read about the Style and Themes on developer.android.com. After some initial success with text color, text size, background color... I seem to get stuck at changing buttons, toggle buttons... It appears to me that to change the color of a button a .9.png file must be created (possibly for the different dpi's). Looking at the artwork in the default style, I see a large number of these .9.png files. To have a consistent style they should all be updated.
Is it correct to say that defining a new style involves modifying/recreating the .9.png files?
If no, how should one go about modifying the style of these .9.png based elements?
If so, are there any tools that assist with creating a custom style? And are there any style packages that can be downloaded/purchased?
I'm not sure it's a good idea to give a new look to every UI control in your application unless you are a very experienced designer. Probably, we can't beat Google designers at their craft and it would be better to comply with existing styles adding some cool features instead of changing button colors at random.
I would like to create a user interface which would contain network indication icons (3G, WiFi...) and I would like to use existing graphic elements which are displayed in notification bar.
Does anyone know how to get these existing elements and use it in custom layout?
I guess these icons are all ImageView elements and I am wondering whether it is possible to retrieve them with findViewById() method.
They are drawables in android.R.drawable. There is a list of avaiable drawables for 1.0 at drawable list
You can go to http://source.android.com/download to get instructions on how to download Android sources (images/drawables included), search for *.pngs and then reference the ones you need like this: getResources().getDrawable(android.R.drawable.ic_menu_save).
P.S. At least some of the drawables come with sdk: $SDK_PATH\platforms\android-1.5\data\res\drawable