Develop Reference

Android Studio: Create Object in custom SwipeButton with attributes from XML

public class SwipeButton extends RelativeLayout {
private ImageView swipeButtonInner;
private float initialX;
private boolean active;
private TextView centerText;
private ViewGroup background;
private Drawable disabledDrawable;
private Drawable enabledDrawable;
private OnStateChangeListener onStateChangeListener;
private OnActiveListener onActiveListener;
private static final int ENABLED = 0;
private static final int DISABLED = 1;
private int collapsedWidth;
private int collapsedHeight;
private LinearLayout layer;
private boolean trailEnabled = false;
private boolean hasActivationState;
public SwipeButton(Context context) {
super(context);
init(context, null, -1, -1);
}
public SwipeButton(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs, -1, -1);
}
public SwipeButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs, defStyleAttr, -1);
}
#TargetApi(21)
public SwipeButton(Context context, AttributeSet attrs, int defStyleAttr, int
defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init(context, attrs, defStyleAttr, defStyleRes);
}
public boolean isActive() {
return active;
}
public void setText(String text) {
centerText.setText(text);
}
public void setBackground(Drawable drawable) {
background.setBackground(drawable);
}
public void setSlidingButtonBackground(Drawable drawable) {
background.setBackground(drawable);
}
public void setDisabledDrawable(Drawable drawable) {
disabledDrawable = drawable;
if (!active) {
swipeButtonInner.setImageDrawable(drawable);
}
}
public void setButtonBackground(Drawable buttonBackground) {
if (buttonBackground != null) {
swipeButtonInner.setBackground(buttonBackground);
}
}
public void setEnabledDrawable(Drawable drawable) {
enabledDrawable = drawable;
if (active) {
swipeButtonInner.setImageDrawable(drawable);
}
}
public void setOnStateChangeListener(OnStateChangeListener
onStateChangeListener) {
this.onStateChangeListener = onStateChangeListener;
}
public void setOnActiveListener(OnActiveListener onActiveListener) {
this.onActiveListener = onActiveListener;
}
public void setInnerTextPadding(int left, int top, int right, int bottom) {
centerText.setPadding(left, top, right, bottom);
}
public void setSwipeButtonPadding(int left, int top, int right, int bottom) {
swipeButtonInner.setPadding(left, top, right, bottom);
}
public void setHasActivationState(boolean hasActivationState) {
this.hasActivationState = hasActivationState;
}
My XML:`
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:id="#+id/AnswerRelativeLayout"
android:layout_height="70dp"
android:orientation="vertical"
tools:context="com.example.dynamicobj.FragmentMain">
<com.example.dynamicobj.SwipeButton
android:id="#+id/test_btn"
android:layout_width="match_parent"
android:layout_height="70dp"
app:button_background="#drawable/shape_button"
app:button_image_disabled="#drawable/ic_launcher_background"
app:button_image_height="60dp"
app:button_image_width="100dp"
app:has_activate_state="true"
app:initial_state="disabled"
app:inner_text="Termine buchen"
app:inner_text_background="#drawable/shape_rounded"
app:inner_text_bottom_padding="18dp"
app:inner_text_right_padding="200dp"
app:inner_text_color="#android:color/black"
app:inner_text_size="16sp"
app:inner_text_top_padding="18dp" />
</LinearLayout>`
F
ragmentMain:
public class FragmentMain extends Fragment {
Context context;
View rootView;
public FragmentMain() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(false);
}
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_main, container, false);
LinearLayout layout = (LinearLayout)
rootView.findViewById(R.id.AnswerRelativeLayout);
SwipeButton button = new SwipeButton(getContext());
layout.addView(button);
return rootView;
}
}
So I got this custom SwipeButton class from Git (com.ebanx.swipebtn.SwipeButton). Now I want to create an Object from SwipeButton with a layout looking like the one from the xml file. Is there any method, where I just can give the new button the prefinished layout without having to use all these Methods in the SwipeButton class? I am going to create the buttons dynamically later on, but all being the same layout. Help pls?

you forgot to add LayoutParams to your button
use below code before adding button into layout
button.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT))
and set your LinearLayout height wrap_content not 70dp

RecyclerView inside NestedScrollView takes too much time when loading large amount of data

RecyclerView inside NestedScrollView freezes the Activity when loading large amount of data. It loads much faster with ScrollView, but scrolling is affected in that case.
I tried setting attributes like setAutoMeasure and setNestedScrollingEnabled which did not help.
Any suggestions?

Recycling of views is not supported inside NestedScrollViews as I understand, so the suggestion would be to try to change your layout.

This help to increase the speed of recycler view scrolling.
SpeedyLinearLayoutManager linearLayoutManager = new SpeedyLinearLayoutManager(MainActivity.this);
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
myRecyclerView.setLayoutManager(linearLayoutManager);
SpeedyLinearLayoutManager.class
public class SpeedyLinearLayoutManager extends LinearLayoutManager {
private static final float MILLISECONDS_PER_INCH = 2f; //default is 25f (bigger = slower)
public SpeedyLinearLayoutManager(Context context) {
super(context);
}
public SpeedyLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
super(context, orientation, reverseLayout);
}
public SpeedyLinearLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
#Override
public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
final LinearSmoothScroller linearSmoothScroller = new LinearSmoothScroller(recyclerView.getContext()) {
#Override
public PointF computeScrollVectorForPosition(int targetPosition) {
return SpeedyLinearLayoutManager.this.computeScrollVectorForPosition(targetPosition);
}
#Override
protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
return MILLISECONDS_PER_INCH / displayMetrics.densityDpi;
}
};
linearSmoothScroller.setTargetPosition(position);
startSmoothScroll(linearSmoothScroller);
}
}

Use Custom list view instead of Recycler view inside scroll view...
Check this Answer
Custom List View
import android.content.Context;
import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.ListView;
public class ExpandableHeightListView extends ListView {
boolean expanded = true;
public ExpandableHeightListView(Context context) {
super(context);
}
public ExpandableHeightListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ExpandableHeightListView(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
}
public boolean isExpanded() {
return expanded;
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// HACK! TAKE THAT ANDROID!
if (isExpanded()) {
// Calculate entire height by providing a very large height hint.
// View.MEASURED_SIZE_MASK represents the largest height possible.
int expandSpec = MeasureSpec.makeMeasureSpec(MEASURED_SIZE_MASK,
MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);
ViewGroup.LayoutParams params = getLayoutParams();
params.height = getMeasuredHeight();
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
public void setExpanded(boolean expanded) {
this.expanded = expanded;
}
}

you can include app:layout_behavior="#string/appbar_scrolling_view_behavior"
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
or disable the nested scrolling behavior for the recycler view.
recyclerView.setNestedScrollingEnabled(false);

How to make the RecyclerView forbid Scroll

In some cases, we need to make the RecyclerView cannot scroll, so play to your strengths for this questions.

I have some solutions for this problem, hope it can help you.See below for details:
void setLayoutFrozen (boolean frozen);
I strongly recommend if we only want to inhabit scroll for this scheme for its simplicity and convenience; if you want to know deeply
When we use LayoutManager(LinearManager or GridLayoutManager), we can use this.
`
LinearLayoutManager linearLayoutManager = new
LinearLayoutManager(mContext, LinearLayoutManager.VERTICAL, false){
#Override
public boolean canScrollVertically() {
return false;
}
#Override
public boolean canScrollHorizontally() {
return super.canScrollHorizontally();
}
};`
GridLayoutManager is alike.
From above second item, we can extend corresponding LayoutManager.
`
public class MyGridLayoutManager extends GridLayoutManager {
private boolean isScrollEnabled = true;
public MyGridLayoutManager(Context context, int spanCount) {
super(context, spanCount);
}
public MyGridLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
public MyGridLayoutManager(Context context, int spanCount, int orientation, boolean reverseLayout) {
super(context, spanCount, orientation, reverseLayout);
}
public void setScrollEnabled(boolean flag) {
this.isScrollEnabled = flag;
}
#Override
public boolean canScrollVertically() {
return isScrollEnabled && super.canScrollVertically();
}
}
`
4. We can handle the RecyclerView TouchEvent to achieve the effect.
From above, I believe you can make yourself. Good Luck...

Cannot resolve method 'super()' error in android studio

I am getting the error: "Cannot resolve method 'super()'" in my code and I am not sure how to resolve this, do you have any clues?
The code is as follows:
public GeoView( double left, double top, double width )
{
super();
this.left = left;
this.top = top;
this.width = width;
this.transform = null;
this.backing_store = null;
this.sink = false;
this.last_size = new Rect(0, 0, 200, 200 );
this.do_tracking = false;
Drawable background = new Drawable() {
#Override
public void draw(Canvas canvas) {
}
#Override
public void setAlpha(int i) {
}
#Override
public void setColorFilter(ColorFilter colorFilter) {
}
#Override
public int getOpacity() {
return 0;
}
};

What is GeoView class? You extended it from another class?
If yes. Check that parent class have empty constructor, because you call it.
If it's your own class and it didn't extended from any other class. Then you don't need to call super().
View doesn't have empty constructor.
You should Have at least one of this constructor.
public GeoView(Context context) {
super(context);
}
public GeoView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public GeoView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
If you want to create view by yourself, you need first constructor. Then you have to
GeoView geoView = new GeoView(YourActivity.this);
Or you can simply add your view to layout. Then You second will be called constructor. I think you should add all of them.
<com.example.yourapp.GeoView
android:layout_height="300dp"
android:layout_width="match_parent"/>

Filling 4 Items in a listview on any device

I'm developing an application that have to show exactly 4 items at a time in a listview, independent of device.
How do I get the size of the list view on the device and set list items height to fit 4 at a time on the screen?

1- extend ListView class
public class CustomListView extends ListView {
public CustomListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public CustomListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomListView(Context context) {
super(context);
}
private Runnable afterLayoutRunnable;
public void setAfterLayoutRunnable(Runnable afterLayoutRunnable) {
this.afterLayoutRunnable = afterLayoutRunnable;
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
if (afterLayoutRunnable != null) {
afterLayoutRunnable.run();
}
}
}
2- create your own ArrayAdapter
public class CustomListAdapter extends ArrayAdapter<MyObject> {
public CustomListAdapter(Context context, int textViewResourceId, List<MyObject> objects) {
super(context, textViewResourceId, objects);
}
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater layoutInflater = (LayoutInflater) getContext().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
convertView = layoutInflater.inflate(R.layout.my_item_layout, null);
int height = TestActivity.listItemsMinimumHieght;
if (height > 0) {
convertView.setMinimumHeight(height);
}
}
}
}
3- in your Activity
public class TestActivity extends Activity {
public static int listItemsMinimumHieght = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final CustomListView customListView = (CustomListView) findViewById(R.id.conversation_activity_button_send);
customListView.setAfterLayoutRunnable(new Runnable() {
#Override
public void run() {
listItemsMinimumHieght = customListView.getHeight() / 4;
ArrayList<MyObject> objects=getListContent();
customListView.setAdapter(new ListViewConversationAdapter(TestActivity.this, R.id.sample, objects));
}
});
}
}
i think this should work, good luck