Develop Reference

Is there a way to set MotionLayout custom attribute for MaterialButton's iconTint?

According to this article
CustomAttribute are specified with the attributeName, which needs to match the getter/setter methods of an object such that:
getter: getName (e.g. getBackgroundColor)
setter: setName (e.g. setBackgroundColor)
(so motion:attributeName need to be backgroundColor)
I've tried bellow attribute names with material button, but none of them worked.
<CustomAttribute motion:attributeName="IconTintResource" motion:customColorValue="#color/keyTextColor" />
'IconTintResource', 'iconTintResource', 'IconTint', 'iconTint', 'ColorFilter'
any suggestions?
These are the errors I'm getting
E/TransitionLayout: Custom Attribute "IconTint" not found on com.google.android.material.button.MaterialButton
E/TransitionLayout: com.google.android.material.button.MaterialButton must have a method setIconTint
E/TransitionLayout: no method setIconTinton View "f_editor_image_view_terminal"

MotionLayout's CustomAttribute use reflection to setValues on Views (roughly based on the Java beans conventions)
So if you say
<CustomAttribute motion:attributeName="foo" motion:customColorValue="#color/keyTextColor" />
It looks for a method setFoo(int value);
Unfortunately even though MaterialButton parses the xml android:iconTint="#FFF"
It does not have the method setIconTint(int color);
MotionLayout will also check for setFoo(Drawable()) and use a ColorDrawable
You can create a subclass of MaterialButton and implement the method needed
setInconTint(int color)
class MyButton extends MaterialButton {
public MyButton(#NonNull Context context) {
super(context);
}
public MyButton(#NonNull Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
}
public MyButton(#NonNull Context context, #Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
void setIconTint(int color) {
ColorStateList colorStateList = new ColorStateList(new int[1][0],new int[]{color});
setIconTint(colorStateList);
}
}
This would then work with MotionLayout. This will create many objects during animation but they will be short lived.

Alter AttributeSet values in android

I am having custom view which will take attribute set(xml value) as constructor value
public CustomView(Context context) // No Attributes in this one.
{
super(context);
this(context, null, 0);
}
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
this(context, attrs, 0)
}
public CustomView(Context context, AttributeSet attrs, int default_style) {
super(context, attrs, default_style);
readAttrs(context, attrs, defStyle);
init();
}
In Fragment class i am setting the view as
CustomView customView = (CustomView) view.findViewById(R.id.customView);
where custom view contains various value such as height,width,padding etc.
i want to modify those values based on required condition and set it back to custom view.
I placed setting width height code in onDraw method and called invalidte view.
But above method will set the every time if i called invalidate method in CustomView class.
how to overcome this so that i can pass modified attribute set value in constructor only.?
Edit: I need to modify the view values(initialize with new values) which is set during attribute constructor so that i will get a refreshed view with a new values.
Override #OnDraw or 'Invalidate' is not a good function for me where inside invalidate i have written the methods which will execute in each second interval.

I see that your CustomView can have multiple attributes and you want to modify some of these attributes based on some condition and pass this in the constructor.
Few best practices while designing a custom view:
If you have custom attributes, make sure that you expose them via setters and getters. In your setter method, call invalidate();
Don't try modifying any attributes inside onDraw() or onMeasure() methods.
Try your best to avoid writing Custom constructors for your Custom View.
So the ideal way to solve your problem is to instantiate your CustomView and then modify the attributes, either externally (in your Activity or Fragment), or have a method inside the CustomView.java and then invoke it externally. Doing this will still give you the same result you are looking for.

So lets say you declared your custom attributes like this for view named StarsView
<declare-styleable name="StarsView">
<attr name="stars" format="integer" />
<attr name="score" format="float" />
</declare-styleable>
And you want to read attributes from something like this
<my.package..StarsView
app:stars="5"
app:score="4.6"
You do just this in constructor
public StarsView(Context context, AttributeSet attrs) {
super(context, attrs);
if(attrs != null) {
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.StarsView, defStyleAttr, 0);
stars = Tools.MathEx.clamp(1, 10, a.getInt(R.styleable.StarsView_stars, 5));
score = (int)Math.floor(a.getFloat(R.styleable.StarsView_score, stars) * 2f);
a.recycle(); // its important to call recycle after we are done
}
}

It's probably not the solution you were hoping for, but put a FrameLayout in your xml instead of the CustomView, and then create your CustomView programmatically with the FrameLayout as it's parent

Custom view constructor does not get called on android 5.0.2

I created a custom view:
public class SomeView extends View
The custom view constructors:
public SomeView (Context context)
{
super(context);
}
// Called when view is inflated from xml
public SomeView (Context context, AttributeSet attrs)
{
super(context, attrs);
}
// Perform inflation from XML and apply a class-specific base style from a theme attribute.
public SomeView (Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
}
I also tried the 4th constructor from api 21 with no luck:
public VeediView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)
{
super(context, attrs,defStyleAttr, defStyleRes);
}
In the xml layout i am defining this view and things work fine.
Testing on Galaxy S2 works fine and the view constructor are called but when running the app on Nexus-7 android 5.0.2 the constructors do not get called at all.
Any idea why?
Could it be related to rooted devices?
The related xml view:
<com.package.name
android:id="#+id/scene"
android:onClick="startx"
style="#style/txt_money_style"
android:layout_width="72dp"
android:layout_height="72dp"
android:background="#drawable/wtbtn"
android:layout_gravity="right"
android:gravity="center_vertical|right"
/>

I think you should use this constructor for bestway:
public SomeView (Context context)
{
this(context , null);
}
// Called when view is inflated from xml
public SomeView (Context context, AttributeSet attrs)
{
this(context, attrs , 0);
}
// Perform inflation from XML and apply a class-specific base style from a theme attribute.
public SomeView (Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
// Initialize customize constructor here
}

In API 21 theres now a 4th constructor it could be that your XML is calling this.
From the docs:
public View (Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)
Added in API level 21
Perform inflation from XML and apply a class-specific base style from a theme attribute or style resource. This constructor of View allows subclasses to use their own base style when they are inflating.
When determining the final value of a particular attribute, there are four inputs that come into play:
Any attribute values in the given AttributeSet.
The style resource specified in the AttributeSet (named "style").
The default style specified by defStyleAttr.
The default style specified by defStyleRes.
The base values in this theme.
Each of these inputs is considered in-order, with the first listed taking precedence over the following ones. In other words, if in the AttributeSet you have supplied , then the button's text will always be black, regardless of what is specified in any of the styles.
Parameters
context The Context the view is running in, through which it can access the current theme, resources, etc.
attrs The attributes of the XML tag that is inflating the view.
defStyleAttr An attribute in the current theme that contains a reference to a style resource that supplies default values for the view. Can be 0 to not look for defaults.
defStyleRes A resource identifier of a style resource that supplies default values for the view, used only if defStyleAttr is 0 or can not be found in the theme. Can be 0 to not look for defaults.

Here is source code of referred View.java class. If you check it out you will see, that public View(Context context) is always called. If you think it's not called but you see the view, then the issue is rather in the part detecting whether it gets called, than in Android code. You should look in there. It could be logging code or some wrong filters in AS, or similar.
From the source code you can also see, that this is the new constructor, used in Android 5.0 an higher, which has the most implementation.
public View(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)

The thing is i got this code and didnt develop it myself and after trying everything it turns out that the app have multiple layout files:
layout-large, layout-small etc...
I only defined the custom view on the layout folder so switching to other screen sizes invoked the regular view.
I guess others can learn from my mistake , i wish Android Studio or Eclipse can support some kind of setContentView(R.layout.activity_scene) and the related file debug option
So the answer is to make sure all layouts have the custom view defined

Android - How to add text style in my entire application

i have Helvetica Neue.ttf in asset Folder , How to set the Helvetica Neue textStyle on My Entire Applcation.

There is currently no way to do this with the Views that come with the Android SDK. You can set your View to use any of the Roboto fonts as per this answer, but you cannot set a custom font.
The way I typically tackle this problem is to create my own TextView that uses my font, like so:
public class MyFontTextView extends TextView {
public static final String FONT_PATH = "fonts/MyFont.ttf";
public MyFontTextView(Context context) {
super(context);
initFont();
}
public MyFontTextView(Context context, AttributeSet attrs) {
super(context, attrs);
initFont();
}
public MyFontTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initFont();
}
/**
* Set up the font.
*/
private void initFont() {
if (!isInEditMode()) {
Typeface font = Typeface.createFromAsset(getContext().getAssets(), FONT_PATH);
setTypeface(font);
}
}
}
You replace all of your TextViews with this TextView, and then you will have your font. Note that other UI elements (e.g. Buttons) will still use Roboto unless you also customize those.
If you have a View that you only use once in your application, you could call setTypeFace() on that View instead of creating a custom View. The custom View method works well for Views that you use a lot in an application such as TextViews.

android: how to set custom font for entire application

I have developed a very huge application and now i have a requirement of having custom font for all controls in the application. so I want to know the better way to change the font in one shot. The application has more than a hundred XML layout. and i cant change all controls to a custom component with custom font. Please provide a solution to Change the font without altering all the controls in XML.

Do something like this
pacage com.prac;
class MyFontedTextView extends TextView {
public FontedTextView(Context context) {
super(context);
init();
}
public FontedTextView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public FontedTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
String otfName = "MyCustomOtfFileWhichIPutInAssetsFolder.otf";
Typeface font = Typeface.createFromAsset(context.getAssets(), otfName);
this.setTypeface(font);
}
}
Now replace this all over in xml file from your TextViews
<com.prac.MyFontedTextView .... instead of <TextView
This change you have to do all over for it to apply
also for the case of button text . Button is also subclass of TextView
So the same can work for button's too
Hope this help or can lead you to the solution you are looking