refactor: remove unused resources, cleanup the code structure

common/src/main/java/com/stardust/app/FragmentPagerAdapterBuilder.java

@@ -0,0 +1,94 @@
+package com.stardust.app;
+
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentManager;
+import android.support.v4.app.FragmentPagerAdapter;
+import android.util.SparseArray;
+import android.view.ViewGroup;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by Stardust on 2017/3/24.
+ */
+
+public class FragmentPagerAdapterBuilder {
+
+    public interface OnFragmentInstantiateListener {
+        void OnInstantiate(int pos, Fragment fragment);
+    }
+
+    private List<Fragment> mFragments = new ArrayList<>();
+    private List<String> mTitles = new ArrayList<>();
+    private FragmentActivity mActivity;
+
+    public FragmentPagerAdapterBuilder(FragmentActivity activity) {
+        mActivity = activity;
+    }
+
+    public FragmentPagerAdapterBuilder add(Fragment fragment, String title) {
+        mFragments.add(fragment);
+        mTitles.add(title);
+        return this;
+    }
+
+    public FragmentPagerAdapterBuilder add(Fragment fragment, int titleResId) {
+        return add(fragment, mActivity.getString(titleResId));
+    }
+
+    public StoredFragmentPagerAdapter build() {
+        return new StoredFragmentPagerAdapter(mActivity.getSupportFragmentManager()) {
+            @Override
+            public Fragment getItem(int position) {
+                return mFragments.get(position);
+            }
+
+            @Override
+            public int getCount() {
+                return mFragments.size();
+            }
+
+            @Override
+            public CharSequence getPageTitle(int position) {
+                return mTitles.get(position);
+            }
+        };
+    }
+
+    public abstract static class StoredFragmentPagerAdapter extends FragmentPagerAdapter {
+
+        private SparseArray<Fragment> mStoredFragments = new SparseArray<>();
+        private OnFragmentInstantiateListener mOnFragmentInstantiateListener;
+
+        public StoredFragmentPagerAdapter(FragmentManager fm) {
+            super(fm);
+        }
+
+        @Override
+        public Object instantiateItem(ViewGroup container, int position) {
+            Fragment fragment = (Fragment) super.instantiateItem(container, position);
+            mStoredFragments.put(position, fragment);
+            if(mOnFragmentInstantiateListener != null){
+                mOnFragmentInstantiateListener.OnInstantiate(position, fragment);
+            }
+            return fragment;
+        }
+
+
+        @Override
+        public void destroyItem(ViewGroup container, int position, Object object) {
+            mStoredFragments.remove(position);
+            super.destroyItem(container, position, object);
+        }
+
+        public Fragment getStoredFragment(int position) {
+            return mStoredFragments.get(position);
+        }
+
+        public void setOnFragmentInstantiateListener(OnFragmentInstantiateListener onFragmentInstantiateListener) {
+            mOnFragmentInstantiateListener = onFragmentInstantiateListener;
+        }
+    }
+}