Select All functionality

app/src/main/java/com/abdeveloper/sampleapplication/MainActivity.java

@@ -70,6 +70,7 @@ protected void onCreate(Bundle savedInstanceState) {
                 .positiveText("Done")
                 .negativeText("Cancel")
                 .setMinSelectionLimit(0)
+                .enableSelectAllItem("Select All", true)
                 .setMaxSelectionLimit(listOfCountries.size())
                 .preSelectIDsList(alreadySelectedCountries) //List of ids that you need to be selected
                 .multiSelectList(listOfCountries) // the multi select model list with ids and name

library/src/main/java/com/abdeveloper/library/MultiSelectDialog.java

@@ -4,13 +4,16 @@
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.v7.app.AppCompatDialogFragment;
+import android.support.v7.widget.AppCompatCheckBox;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.SearchView;
 import android.util.TypedValue;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.Window;
 import android.view.WindowManager;
+import android.widget.CompoundButton;
+import android.widget.LinearLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -41,6 +44,9 @@ public class MultiSelectDialog extends AppCompatDialogFragment implements Search
     private int maxSelectionLimit = 0;
     private String maxSelectionMessage = null;
 
+    private String selectAllItemText = null;
+    private boolean select_selectAllItemOnCreate = false;
+
     @NonNull
     @Override
     public Dialog onCreateDialog(Bundle savedInstanceState) {
@@ -69,15 +75,48 @@ public Dialog onCreateDialog(Bundle savedInstanceState) {
 
         settingValues();
 
+        if(this.select_selectAllItemOnCreate) {
+            previouslySelectedIdsList.clear();
+
+            for(int i = 0; i < mainListOfAdapter.size(); i++) {
+                previouslySelectedIdsList.add(mainListOfAdapter.get(i).getId());
+            }
+        }
+
+        final AppCompatCheckBox selectAllCheckBox = (AppCompatCheckBox) dialog.findViewById(R.id.select_all_checkbox);
+        LinearLayout selectAllContainer = (LinearLayout) dialog.findViewById(R.id.select_all_container);
+
         mainListOfAdapter = setCheckedIDS(mainListOfAdapter, previouslySelectedIdsList);
-        mutliSelectAdapter = new MutliSelectAdapter(mainListOfAdapter, getContext());
+
+        mutliSelectAdapter = new MutliSelectAdapter(mainListOfAdapter, getContext(), selectAllCheckBox);
         mrecyclerView.setAdapter(mutliSelectAdapter);
 
+        if(this.selectAllItemText != null) {
+            dialog.findViewById(R.id.select_all_container).setVisibility(View.VISIBLE);
+            ((TextView)dialog.findViewById(R.id.select_all_text)).setText(this.selectAllItemText);
+
+            selectAllContainer.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View view) {
+                    selectAllCheckBox.setChecked(!selectAllCheckBox.isChecked());
+                }
+            });
+            selectAllCheckBox.setClickable(true);
+            selectAllCheckBox.setChecked(this.select_selectAllItemOnCreate);
+            selectAllCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+                @Override
+                public void onCheckedChanged(CompoundButton compoundButton, boolean selected) {
+                    if(selected) {
+                        mutliSelectAdapter.selectAll();
+                    }
+                }
+            });
+        }
+
         searchView.setOnQueryTextListener(this);
         searchView.onActionViewExpanded();
         searchView.clearFocus();
 
-
         return dialog;
     }
 
@@ -135,6 +174,17 @@ public MultiSelectDialog setMinSelectionMessage(String message) {
 		return this;
 	}
 
+	public MultiSelectDialog enableSelectAllItem(String itemText, boolean selectOnCreate) {
+        if(itemText == null || itemText.length() == 0) {
+            throw new IllegalArgumentException("Argument itemText cannot be null or empty");
+        }
+
+        this.selectAllItemText = itemText;
+        this.select_selectAllItemOnCreate = selectOnCreate;
+
+        return this;
+    }
+
     public MultiSelectDialog onSubmit(@NonNull SubmitCallbackListener callback) {
         this.submitCallbackListener = callback;
         return this;

library/src/main/java/com/abdeveloper/library/MutliSelectAdapter.java

@@ -22,10 +22,12 @@ class MutliSelectAdapter extends RecyclerView.Adapter<MutliSelectAdapter.MultiSe
     private ArrayList<MultiSelectModel> mDataSet = new ArrayList<>();
     private String mSearchQuery = "";
     private Context mContext;
+    private AppCompatCheckBox mSelectAllCheckBox;
 
-    MutliSelectAdapter(ArrayList<MultiSelectModel> dataSet, Context context) {
+    MutliSelectAdapter(ArrayList<MultiSelectModel> dataSet, Context context, AppCompatCheckBox selectAllCheckBox) {
         this.mDataSet = dataSet;
         this.mContext = context;
+        this.mSelectAllCheckBox = selectAllCheckBox;
     }
 
     @Override
@@ -39,23 +41,22 @@ public void onBindViewHolder(final MultiSelectDialogViewHolder holder, int posit
 
         if (!mSearchQuery.equals("") && mSearchQuery.length() > 1) {
             setHighlightedText(position, holder.dialog_name_item);
-        } else {
+        }
+        else {
             holder.dialog_name_item.setText(mDataSet.get(position).getName());
         }
 
         if (mDataSet.get(position).getSelected()) {
-
             if (!MultiSelectDialog.selectedIdsForCallback.contains(mDataSet.get(position).getId())) {
                 MultiSelectDialog.selectedIdsForCallback.add(mDataSet.get(position).getId());
             }
         }
-
-        if (checkForSelection(mDataSet.get(position).getId())) {
-            holder.dialog_item_checkbox.setChecked(true);
-        } else {
-            holder.dialog_item_checkbox.setChecked(false);
+        else if(mSelectAllCheckBox != null) {
+            mSelectAllCheckBox.setChecked(false);
         }
 
+        holder.dialog_item_checkbox.setChecked(checkForSelection(mDataSet.get(position).getId()));
+
         /*holder.dialog_item_checkbox.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
@@ -117,6 +118,13 @@ private boolean checkForSelection(Integer id) {
         return false;
     }
 
+    public void selectAll() {
+        for(int i = 0; i < mDataSet.size(); i++) {
+            mDataSet.get(i).setSelected(true);
+        }
+
+        this.notifyDataSetChanged();
+    }
 
     /*//get selected name string seperated by coma
     public String getDataString() {

library/src/main/res/layout/custom_multi_select.xml

@@ -25,7 +25,8 @@
         android:iconifiedByDefault="true"
         android:queryHint="Search" />
 
-    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    <LinearLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
         android:id="@+id/select_all_container"
         android:visibility="gone"
         android:layout_width="match_parent"