I am trying to extend a cardview to set the background image. I know that this can not be done with normal cardview. I have searched net and found plenty of solutions for setting a background color to the card view but none for image.
My code to do so:
public class CCView extends CardView {
public CCView (Context context) {
super(context);
init();
}
public CCView (Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public CCView (Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
setBackground(getResources().getDrawable(R.drawable.cc_background));
}
}
I get this exception when I populate the code from XML
android.graphics.drawable.BitmapDrawable cannot be cast to android.support.v7.widget.RoundRectDrawableWithShadow
Any solution?
As CardView extends FrameLayout you can layer layouts on top of it. To get around the problem you're having, I'd try adding a blank view "underneath" all the other elements in your view, and then set that view to inherit the state of its parent. Something like this:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_height="match_parent"
android:layout_width="match_parent"
card_view:cardBackgroundColor="#DDFFFFFF"
card_view:cardElevation="#dimen/card_elevation">
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:duplicateParentState="true"
android:background="#drawable/card_background"/>
<LinearLayout
....
....
....
/LinearLayout>
</android.support.v7.widget.CardView>
Related
I created custom view based on Toolbar:
public class CommonToolbar extends Toolbar {
public CommonToolbar(Context context, AttributeSet attrs) {
super(context, attrs);
LayoutInflater.from(context).inflate(R.layout.common_toolbar, this, true);
}
common_toolbar.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="32dp"
android:background="#color/colorPrimary"
app:contentInsetStart="0dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/backIcon"
style="#style/ToolbarNavigationButton"
app:srcCompat="#drawable/icon_close" />
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:layout_toEndOf="#+id/backIcon"
android:gravity="center"
android:text="Title"
android:textStyle="bold" />
</RelativeLayout>
</android.support.v7.widget.Toolbar>
As you can see i set attribute contentInsetStart value to 0, but when i use this Toolbar in any layout file, padding is still present (image). I can modify this by changing contentInsetStart value in destination layout file, but I prefer to keep this in source xml. Why is it happening?
Because your custom view extends Toolbar you are inflating your xml toolbar into a Toolbar. If you take a look at your layout with Layout Inspector, your view hierarchy will look like this:
<CommonToolbar> (Subclass of Toolbar)
<Toolbar>
<RelativeLayout>
...
So when you set contentInsetStart via xml, you are setting it on the inner toolbar. The outer toolbar still has a content inset.
To avoid this you can have Common Toolbar extend a ViewGroup i.e.
public class CommonToolbar extends RelativeLayout {
public CommonToolbar(Context context, AttributeSet attrs) {
super(context, attrs);
LayoutInflater.from(context).inflate(R.layout.common_toolbar, this, true);
}
Or inflate the common toolbar using an include tag. i.e.
<include
layout="#layout/common_toolbar"
/>
which allows you to remove the CommonToolbar custom view
Use setContentInsetsAbsolute(0, 0);
public class CustomToolbar extends Toolbar {
#BindView(R.id.txt_screen_title)
TextView txtScreenTitle;
public CustomToolbar(Context context) {
super(context);
initToolbarLayout(context);
}
public CustomToolbar(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
initToolbarLayout(context);
}
public CustomToolbar(Context context, #Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initToolbarLayout(context);
}
private void initToolbarLayout(Context context) {
View toolbarView = LayoutInflater.from(context).inflate(R.layout.app_toolbar, null);
this.addView(toolbarView);
ButterKnife.bind(this, toolbarView);
setContentInsetsAbsolute(0, 0);
}
public void setScreenTitle(String title) {
if(txtScreenTitle != null) {
txtScreenTitle.setText(title);
}
}
}
I need to create my own ImageView.
This is my class:
public class Brick extends ImageView implements Serializable{
public Brick(Context context) {
super(context);
}
public Brick(Context context, AttributeSet attrs) {
super(context, attrs);
}
public Brick(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
}
When I try to use my ImageView inside a xml layout file (as you can see below) I have a problem. I can see a black shape, but there is not the image (the drawable called d) inside it.
<com.myapp.Brick
android:id="#+id/myBrick"
app:srcCompat="#drawable/d"
android:background="#000000"
android:layout_width="300dp"
android:layout_height="300dp" />
What's my error?
You should call android:src="#drawable in your XML Section .
<com.myapp.Brick
android:id="#+id/myBrick"
app:srcCompat="#drawable/d"
android:background="#000000" // showing Black Shape Background
android:layout_width="300dp"
android:layout_height="300dp"
android:src="#drawable/add_image /> // Add android:src
You should add app:srcCompat or android:src in your XML Section
I have a hierarchy of custom views that looks like this:
Activity(RelativeLayout) -> ParentLayout(FrameLayout) -> ChildLayout(LinearLayout)
The activity and parent layout are added and displayed just fine, but the child is not. I have looked at the hierarchy viewer in the device monitor to confirm it is not being added to the view hierarchy.
Really all I'm trying to do here is create a view hierarchy so I can play around with handling touch events at various places in the view.
Here is everything:
main_activity.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity">
<net.openeye.touchevents.ParentLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#558833" />
</RelativeLayout>
parent_layout.xml:
<?xml version="1.0" encoding="utf-8"?>
<net.openeye.touchevents.ParentLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<net.openeye.touchevents.ChildLayout
android:id="#+id/child_view"
android:layout_width="300dp"
android:layout_height="300dp" />
</net.openeye.touchevents.ParentLayout>
ParentLayout.java:
public class ParentLayout extends FrameLayout implements View.OnTouchListener {
public ParentLayout(Context context) {
super(context);
}
public ParentLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ParentLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
}
child_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<net.openeye.touchevents.ChildLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="300dp"
android:background="#0066dd"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Hi"/>
</net.openeye.touchevents.ChildLayout>
ChildLayout.java:
public class ChildLayout extends LinearLayout {
public ChildLayout(Context context) {
super(context);
}
public ChildLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ChildLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
}
What am I missing? I have another project that is basically set up the same way, except the child views are dynamically inflated and added, instead of being directly added in the xml layout files. This seems like it should work and I don't understand why it doesn't.
So it looks like when you have a custom view class, you don't want to have the view of the layout file be the same type as the custom class. i.e., if I have ParentLayout.java, I don't want parent_layout.xml's root to be <net.openeye.TouchEvents.ParentLayout>. It seems that when you want both a custom layout file and custom view class, you need to have the view class inflate the layout. If the layout has an element (the root, on this case) that is the same as the class, it will cause infinite recursion as the view inflates the layout, which instantiates the class, which inflates the layout... and so on.
I got this to work finally by making the following changes:
parent_layout.xml:
Change the root element from net.openeye.TouchEvents.ParentLayout to the class it extends, FrameLayout. It now looks like this:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- ... -->
</FrameLayout>
child_layout.xml:
Change the root element from net.openeye.TouchEvents.ChildLayout to the class it extends, LinearLayout. It now looks like this:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="300dp"
android:orientation="vertical">
<!-- ... -->
</LinearLayout>
ParentLayout.java: Inflate it's layout during instantiation. It now looks like this:
public ParentLayout(Context context) {
super(context);
init(context);
}
public ParentLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public ParentLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
private void init(Context context) {
inflate(context, R.layout.parent_layout, this);
}
ChildLayout.java: Same thing as ParentLayout.java, but inflate child_layout.
After getting this working and thinking about why this is happening, it makes sense that this is how it works.
As the title, i want to know if there is a the best way to control a view that added dynamically. (we have to keep reference to the view that was added)
Some time, for a complex request we have to add view in runtime. The is some ways to do that. In my case:
Some time i use a listview/recyclerview and control view via the list/recycleview adapter.
Other way is use a hashmap.
Do you have any other ideas? and how it work?
I prefer way, when I define View both by Java and XML file. View created like this, gives you ability to call your own Java methods, but you don`t need to create whole layout dynamically in Java. Little example:
MyView.java:
public class MyView extends LinearLayout {
TextView textView;
public MyView(Context context) {
super(context);
init();
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MyView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
public void init() {
inflate(getContext(), R.layout.my_view, this);
setOrientation(VERTICAL);
textView = (TextView) findViewById(R.id.text_view);
}
public MyView setContent(String value) {
textView.setText(value);
return this;
}
}
my_view.xml:
<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:id="#+id/text_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</merge>
After that, you can simply add it in you layout through Java:
cont.addView(new MyView(this).setContent("Value"));
or xml:
<com.path.to.your.view.MyView
android:id="#+id/my_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
custom view inside of a custom viewGroup not visible, how can I get it to show up?
or is there a better way to do this that would work?
no compile or runtime errors but the view does not show up in the viewGroup, it is supposed to fill the area with color like the other views but it is white and the color for the view is not showing up inside of the CustomLayout
xml code, the first 2 views show up with no problems but the 3rd view that is nested inside of the CustomLayout does not show up, just white color area, the view inside not visible
CustomViewOne is a separate class file, CustomViewTwo and CustomViewThree are both nested inside the MainActivity class as static inner classes, and CustomLayout is a separate file
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >
<com.example.customviewexample.CustomViewOne
android:layout_width="100dp"
android:layout_height="50dp" />
<view
class="com.example.customviewexample.MainActivity$CustomViewTwo"
android:layout_width="100dp"
android:layout_height="50dp" />
<com.example.customviewexample.CustomLayout
android:layout_width="100dp"
android:layout_height="50dp">
<view
class="com.example.customviewexample.MainActivity$CustomViewThree"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</com.example.customviewexample.CustomLayout>
</LinearLayout>
here is the code for the CustomViewThree, vary simple like the other custom Views it just fills the area with color, it is nested inside of the MainActivity so you have to use MainActivity$CustomViewThree to access it.
public static class CustomViewThree extends View {
public CustomViewThree(Context context) {
super(context);
}
public CustomViewThree(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomViewThree(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.GREEN);
}
}
and here is the code for the CustomLayout class
public class CustomLayout extends FrameLayout {
public CustomLayout(Context context) {
super(context);
init(context);
}
public CustomLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public CustomLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
public void init(Context context) {
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
}
}
custom view inside of a custom viewGroup not visible, how can I get it
to show up?
Your parent CustomLayout which wraps the child has a empty onLayout() method which makes the child to not appear. This method is important in a ViewGroup because it's used by the widget to place its children in it. So, you need to provide an implementation for this method to place the children(by calling the layout() method on each of them with the proper positions). As CustomLayout extends FrameLayout you could just call the super method to use FrameLayout's implementation or even better remove the overridden method(is there a reason for implementing it?).