Create Dialog to edit TARE factors

This CL is the base framework for creating and adjusting TARE factor
values. TareFactorDialogFragment sets the basic outline for a factor
that uses a DialogBox to adjust the value. It takes the "title" or name
of the factor, the key that will be associated with the factor, and an
initial value for the factor; then sets up everything so that the factor
value can be easily changed and stored. These factors are also
registered into the settings observer class.

Bug: 195055619
Bug: 193238774

Test: Manual (Made a temporary class instance of the DialogFragment and
showed it in inactive apps onResume())

Change-Id: I3bb67717175e70eab3bbb11f4a42ee63a42f60bc

src/com/android/settings/development/tare/TareFactorDialogFragment.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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.android.settings.development.tare;
+
+import android.app.Dialog;
+import android.content.Context;
+import android.os.Bundle;
+import android.text.InputType;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.EditText;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.fragment.app.DialogFragment;
+
+import com.android.settings.R;
+import com.android.settings.Utils;
+
+/**
+ * Dialog Fragment for changing tare factor values
+ */
+public class TareFactorDialogFragment extends DialogFragment {
+
+    private static final String TAG = "TareDialogFragment";
+
+    private final String mFactorKey;
+    private final String mFactorTitle;
+    private final int mFactorValue;
+    private int mFactorEditedValue;
+
+    private EditText mFactorValueView;
+
+    /**
+     * @param title        the title that will show at the top of the Dialog for the Factor
+     * @param key          the key of the Factor being initialized.
+     * @param defaultValue the initial value set for the Factor before any changes
+     */
+    public TareFactorDialogFragment(@NonNull String title, @NonNull String key, int defaultValue) {
+        mFactorTitle = title;
+        mFactorKey = key;
+        mFactorValue = defaultValue;
+    }
+
+    /**
+     * Gets the current value of the Factor
+     */
+    private String getFactorValue() {
+        // TODO: Get value from locally cached copy
+        return Integer.toString(mFactorEditedValue);
+    }
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(
+                getActivity())
+                .setTitle(mFactorTitle)
+                .setView(createDialogView())
+                .setPositiveButton(R.string.tare_dialog_confirm_button_title, (dialog, which) -> {
+
+                    final String stringValue = mFactorValueView.getText().toString();
+                    mFactorEditedValue = mFactorValue;
+                    try {
+                        mFactorEditedValue = Integer.parseInt(stringValue);
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Error converting '" + stringValue + "' to integer. Using "
+                                + mFactorValue + " instead", e);
+                    }
+                    // TODO: Update csv with new factor value
+                })
+                .setNegativeButton(android.R.string.cancel, (dialog, which) -> {
+                    // TODO: Add proper dismiss for negative button press
+                });
+
+        return builder.create();
+    }
+
+    /**
+     * Creates a view for the factor Dialog that currently
+     * is linked to the basic dialog_edittext.xml layout.
+     */
+    private View createDialogView() {
+        final LayoutInflater layoutInflater = (LayoutInflater) getActivity()
+                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+        View layout = layoutInflater.inflate(R.layout.dialog_edittext, null);
+        mFactorValueView = layout.findViewById(R.id.edittext);
+        mFactorValueView.setInputType(InputType.TYPE_CLASS_NUMBER);
+        mFactorValueView.setText(getFactorValue());
+        Utils.setEditTextCursorPosition(mFactorValueView);
+
+        return layout;
+    }
+}