Add TaskPreference

app/src/main/java/com/hippo/ehviewer/preference/TaskPreference.java

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2016 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hippo.ehviewer.preference;
+
+import android.app.Dialog;
+import android.content.Context;
+import android.os.AsyncTask;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.support.annotation.CallSuper;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v7.app.AlertDialog;
+import android.util.AttributeSet;
+
+import com.hippo.ehviewer.EhApplication;
+import com.hippo.ehviewer.R;
+import com.hippo.preference.DialogPreference;
+import com.hippo.yorozuya.IntIdGenerator;
+
+public abstract class TaskPreference extends DialogPreference {
+
+    private Task mTask;
+    private int mTaskId = IntIdGenerator.INVALID_ID;
+
+    public TaskPreference(Context context) {
+        super(context);
+    }
+
+    public TaskPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public TaskPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    @Override
+    protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
+        builder.setTitle(null);
+        builder.setView(R.layout.preference_dialog_task);
+        builder.setCancelable(false);
+    }
+
+    @Override
+    protected void onDialogCreated(AlertDialog dialog) {
+        if (null == mTask) {
+            mTask = onCreateTask();
+            mTask.setPreference(this);
+            mTaskId = ((EhApplication) getContext().getApplicationContext()).putGlobalStuff(mTask);
+            mTask.execute();
+        }
+    }
+
+    protected void onTaskEnd() {
+        // Dismiss dialog
+        Dialog dialog = getDialog();
+        if (null != dialog) {
+            dialog.dismiss();
+        }
+        // Clear async
+        mTask = null;
+        mTaskId = IntIdGenerator.INVALID_ID;
+    }
+
+    @NonNull
+    protected abstract Task onCreateTask();
+
+    @Override
+    public void onActivityDestroy() {
+        super.onActivityDestroy();
+
+        if (null != mTask) {
+            mTask.setPreference(null);
+        }
+    }
+
+    @Override
+    protected Parcelable onSaveInstanceState() {
+        final Parcelable superState = super.onSaveInstanceState();
+        final SavedState myState = new SavedState(superState);
+        myState.asyncTaskId = mTaskId;
+        return myState;
+    }
+
+    @Override
+    protected void onRestoreInstanceState(Parcelable state) {
+        if (state == null || !state.getClass().equals(SavedState.class)) {
+            // Didn't save state for us in onSaveInstanceState
+            super.onRestoreInstanceState(state);
+            return;
+        }
+
+        SavedState myState = (SavedState) state;
+        mTaskId = myState.asyncTaskId;
+        if (IntIdGenerator.INVALID_ID != mTaskId) {
+            Object o = ((EhApplication) getContext().getApplicationContext()).getGlobalStuff(mTaskId);
+            if (o instanceof Task) {
+                mTask = (Task) o;
+                mTask.setPreference(this);
+            }
+        }
+        if (null == mTask) {
+            mTaskId = IntIdGenerator.INVALID_ID;
+        }
+
+        // TODO if not task, show not reopen dialog
+
+        super.onRestoreInstanceState(myState.getSuperState());
+    }
+
+    private static class SavedState extends BaseSavedState {
+        int asyncTaskId;
+
+        public SavedState(Parcel source) {
+            super(source);
+            asyncTaskId = source.readInt();
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest, int flags) {
+            super.writeToParcel(dest, flags);
+            dest.writeInt(asyncTaskId);
+        }
+
+        public SavedState(Parcelable superState) {
+            super(superState);
+        }
+
+        public static final Parcelable.Creator<SavedState> CREATOR =
+                new Parcelable.Creator<SavedState>() {
+                    @Override
+                    public SavedState createFromParcel(Parcel in) {
+                        return new SavedState(in);
+                    }
+
+                    @Override
+                    public SavedState[] newArray(int size) {
+                        return new SavedState[size];
+                    }
+                };
+    }
+
+    public abstract static class Task extends AsyncTask<Void, Void, Object> {
+
+        private final EhApplication mApplication;
+        @Nullable
+        private TaskPreference mPreference;
+
+        public Task(@NonNull Context context) {
+            mApplication = (EhApplication) context.getApplicationContext();
+        }
+
+        @Nullable
+        public TaskPreference getPreference() {
+            return mPreference;
+        }
+
+        public void setPreference(@Nullable TaskPreference preference) {
+            mPreference = preference;
+        }
+
+        @CallSuper
+        @Override
+        protected void onPostExecute(Object o) {
+            mApplication.removeGlobalStuff(this);
+            if (null != mPreference) {
+                mPreference.onTaskEnd();
+            }
+        }
+    }
+}