Changes for testing CalculatorFormula

Bug: 33458518
Test: manual - compiles, and can still enter, calculate, and inflate
the context menus on API 21 and 25.
Change-Id: Ib5f01e89854248c77cb6484bca46086f34be1ca7

4 files changed, 64 insertions, 44 deletions

diff --git a/src/com/android/calculator2/Calculator.java b/src/com/android/calculator2/Calculator.java
index 96bf44d..9af6bc1 100644
--- a/src/com/android/calculator2/Calculator.java
+++ b/src/com/android/calculator2/Calculator.java
@@ -44,6 +44,7 @@ import android.graphics.Rect;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.StringRes;
 import android.support.v4.content.ContextCompat;
 import android.support.v4.view.ViewPager;
 import android.text.Editable;
@@ -166,7 +167,22 @@ public class Calculator extends Activity
         }
     };
 
-    public final OnDisplayMemoryOperationsListener mOnDisplayMemoryOperationsListener =
+    private final Evaluator.Callback mEvaluatorCallback = new Evaluator.Callback() {
+        @Override
+        public void onMemoryStateChanged() {
+            mFormulaText.onMemoryStateChanged();
+        }
+
+        @Override
+        public void showMessageDialog(@StringRes int title, @StringRes int message,
+                @StringRes int positiveButtonLabel, String tag) {
+            AlertDialogFragment.showMessageDialog(Calculator.this, title, message,
+                    positiveButtonLabel, tag);
+
+        }
+    };
+
+    private final OnDisplayMemoryOperationsListener mOnDisplayMemoryOperationsListener =
             new OnDisplayMemoryOperationsListener() {
         @Override
         public boolean shouldDisplayMemory() {
@@ -174,7 +190,7 @@ public class Calculator extends Activity
         }
     };
 
-    public final OnFormulaContextMenuClickListener mOnFormulaContextMenuClickListener =
+    private final OnFormulaContextMenuClickListener mOnFormulaContextMenuClickListener =
             new OnFormulaContextMenuClickListener() {
         @Override
         public boolean onPaste(ClipData clip) {
@@ -398,6 +414,7 @@ public class Calculator extends Activity
         mResultText = (CalculatorResult) findViewById(R.id.result);
         mFormulaContainer = (HorizontalScrollView) findViewById(R.id.formula_container);
         mEvaluator = Evaluator.getInstance(this);
+        mEvaluator.setCallback(mEvaluatorCallback);
         mResultText.setEvaluator(mEvaluator, Evaluator.MAIN_INDEX);
         KeyMaps.setActivity(this);
 
@@ -950,16 +967,11 @@ public class Calculator extends Activity
     }
 
     // Reevaluation completed; ask result to redisplay current value.
-    public void onReevaluate(long index)
-    {
+    public void onReevaluate(long index) {
         // Index is Evaluator.MAIN_INDEX.
         mResultText.onReevaluate(index);
     }
 
-    public void onMemoryStateChanged() {
-        mFormulaText.onMemoryStateChanged();
-    }
-
     @Override
     public void onTextSizeChanged(final TextView textView, float oldSize) {
         if (mCurrentState != CalculatorState.INPUT) {
@@ -1253,16 +1265,16 @@ public class Calculator extends Activity
     @Override
     public void onClick(AlertDialogFragment fragment, int which) {
         if (which == DialogInterface.BUTTON_POSITIVE) {
-            if (fragment.getTag() == HistoryFragment.CLEAR_DIALOG_TAG) {
+            if (HistoryFragment.CLEAR_DIALOG_TAG.equals(fragment.getTag())) {
                 // TODO: Try to preserve the current, saved, and memory expressions. How should we
                 // handle expressions to which they refer?
                 mEvaluator.clearEverything();
                 // TODO: It's not clear what we should really do here. This is an initial hack.
                 // May want to make onClearAnimationEnd() private if/when we fix this.
                 onClearAnimationEnd();
-                onMemoryStateChanged();
+                mEvaluatorCallback.onMemoryStateChanged();
                 onBackPressed();
-            } else if (fragment.getTag() == Evaluator.TIMEOUT_DIALOG_TAG) {
+            } else if (Evaluator.TIMEOUT_DIALOG_TAG.equals(fragment.getTag())) {
                 // Timeout extension request.
                 mEvaluator.setLongTimeout();
             } else {
diff --git a/src/com/android/calculator2/CalculatorFormula.java b/src/com/android/calculator2/CalculatorFormula.java
index b342792..2911df8 100644
--- a/src/com/android/calculator2/CalculatorFormula.java
+++ b/src/com/android/calculator2/CalculatorFormula.java
@@ -55,9 +55,9 @@ public class CalculatorFormula extends AlignedTextView implements MenuItem.OnMen
     private final ClipboardManager mClipboardManager;
 
     private int mWidthConstraint = -1;
-    protected ActionMode mActionMode;
+    private ActionMode mActionMode;
     private ActionMode.Callback mPasteActionModeCallback;
-    protected ContextMenu mContextMenu;
+    private ContextMenu mContextMenu;
     private OnTextSizeChangeListener mOnTextSizeChangeListener;
     private OnFormulaContextMenuClickListener mOnContextMenuClickListener;
     private Calculator.OnDisplayMemoryOperationsListener mOnDisplayMemoryOperationsListener;
@@ -184,20 +184,6 @@ public class CalculatorFormula extends AlignedTextView implements MenuItem.OnMen
         return lastFitTextSize;
     }
 
-    private static boolean startsWith(CharSequence whole, CharSequence prefix) {
-        int wholeLen = whole.length();
-        int prefixLen = prefix.length();
-        if (prefixLen > wholeLen) {
-            return false;
-        }
-        for (int i = 0; i < prefixLen; ++i) {
-            if (prefix.charAt(i) != whole.charAt(i)) {
-                return false;
-            }
-        }
-        return true;
-    }
-
     /**
      * Functionally equivalent to setText(), but explicitly announce changes.
      * If the new text is an extension of the old one, announce the addition.
@@ -377,7 +363,7 @@ public class CalculatorFormula extends AlignedTextView implements MenuItem.OnMen
     }
 
     private boolean isMemoryEnabled() {
-        return !(mOnDisplayMemoryOperationsListener == null || mOnContextMenuClickListener == null)
+        return mOnDisplayMemoryOperationsListener != null
                 && mOnDisplayMemoryOperationsListener.shouldDisplayMemory();
     }
 
diff --git a/src/com/android/calculator2/Evaluator.java b/src/com/android/calculator2/Evaluator.java
index 604f31a..ab32bc2 100644
--- a/src/com/android/calculator2/Evaluator.java
+++ b/src/com/android/calculator2/Evaluator.java
@@ -16,13 +16,13 @@
 
 package com.android.calculator2;
 
-import android.app.Activity;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Handler;
 import android.preference.PreferenceManager;
+import android.support.annotation.StringRes;
 import android.support.annotation.VisibleForTesting;
 import android.text.Spannable;
 import android.util.Log;
@@ -100,11 +100,10 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
 
     public static String TIMEOUT_DIALOG_TAG = "timeout";
 
-    public static Evaluator getInstance(Calculator calculator) {
+    public static Evaluator getInstance(Context context) {
         if (evaluator == null) {
-            evaluator = new Evaluator(calculator.getApplicationContext());
+            evaluator = new Evaluator(context.getApplicationContext());
         }
-        evaluator.mCalculator = calculator;
         return evaluator;
     }
 
@@ -255,7 +254,11 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     // estimating exponent size for truncating short representation.
     private static final int EXP_COST = 3;
 
-    private Calculator mCalculator;
+    // Listener that reports changes to the state (empty/filled) of memory. Protected for testing.
+    private Callback mCallback;
+
+    // Context for database helper.
+    private Context mContext;
 
     //  A hopefully unique name associated with mSaved.
     private String mSavedName;
@@ -270,7 +273,7 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     public static final int INVALID_MSD = Integer.MAX_VALUE;
 
     // Used to represent an erroneous result or a required evaluation. Not displayed.
-    public static final String ERRONEOUS_RESULT = "ERR";
+    private static final String ERRONEOUS_RESULT = "ERR";
 
     /**
      * An individual CalculatorExpr, together with its evaluation state.
@@ -337,6 +340,7 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     }
 
     Evaluator(Context context) {
+        mContext = context;
         setMainExpr(new ExprInfo(new CalculatorExpr(), false));
         mSavedName = "none";
         mTimeoutHandler = new Handler();
@@ -378,6 +382,14 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     }
 
     /**
+     * Set the Callback for showing dialogs and notifying the UI about memory state changes.
+     * @param callback
+     */
+    public void setCallback(Callback callback) {
+        mCallback = callback;
+    }
+
+    /**
      * Result of initial asynchronous result computation.
      * Represents either an error or a result computed to an initial evaluation precision.
      */
@@ -407,7 +419,9 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     }
 
     private void displayCancelledMessage() {
-        AlertDialogFragment.showMessageDialog(mCalculator, 0, R.string.cancelled, 0, null);
+        if (mCallback != null) {
+            mCallback.showMessageDialog(0, R.string.cancelled, 0, null);
+        }
     }
 
     // Timeout handling.
@@ -456,9 +470,10 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     private static final int QUICK_MAX_RESULT_BITS = 150000;
 
     private void displayTimeoutMessage(boolean longTimeout) {
-        AlertDialogFragment.showMessageDialog(mCalculator, R.string.dialog_timeout,
-                R.string.timeout, longTimeout ? 0 : R.string.ok_remove_timeout,
-                TIMEOUT_DIALOG_TAG);
+        if (mCallback != null) {
+            mCallback.showMessageDialog(R.string.dialog_timeout, R.string.timeout,
+                    longTimeout ? 0 : R.string.ok_remove_timeout, TIMEOUT_DIALOG_TAG);
+        }
     }
 
     public void setLongTimeout() {
@@ -1592,6 +1607,10 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
         mSharedPrefs.edit()
                 .putLong(KEY_PREF_MEMORY_INDEX, index)
                 .apply();
+
+        if (mCallback != null) {
+            mCallback.onMemoryStateChanged();
+        }
     }
 
     /**
@@ -1638,7 +1657,6 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
      * The expression at index is presumed to have been evaluated.
      */
     public void copyToMemory(long index) {
-        mCalculator.onMemoryStateChanged();
         setMemoryIndex((index == MAIN_INDEX) ? preserve(false) : index);
     }
 
@@ -1867,7 +1885,7 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
     }
 
     public Spannable getExprAsSpannable(long index) {
-        return getExpr(index).toSpannableStringBuilder(mCalculator);
+        return getExpr(index).toSpannableStringBuilder(mContext);
     }
 
     /**
@@ -1905,4 +1923,10 @@ public class Evaluator implements CalculatorExpr.ExprResolver {
         mExprDB.close();
         evaluator = null;
     }
+
+    public interface Callback {
+        void onMemoryStateChanged();
+        void showMessageDialog(@StringRes int title, @StringRes int message,
+                @StringRes int positiveButtonLabel, String tag);
+    }
 }
diff --git a/src/com/android/calculator2/HistoryFragment.java b/src/com/android/calculator2/HistoryFragment.java
index 86ab138..9c9c573 100644
--- a/src/com/android/calculator2/HistoryFragment.java
+++ b/src/com/android/calculator2/HistoryFragment.java
@@ -137,8 +137,8 @@ public class HistoryFragment extends Fragment {
         super.onActivityCreated(savedInstanceState);
 
         final Calculator activity = (Calculator) getActivity();
-
-        mAdapter.setEvaluator(Evaluator.getInstance(activity));
+        mEvaluator = Evaluator.getInstance(activity);
+        mAdapter.setEvaluator(mEvaluator);
 
         final boolean isResultLayout = activity.isResultLayout();
 
@@ -146,8 +146,6 @@ public class HistoryFragment extends Fragment {
         mDragLayout.removeDragCallback(mDragCallback);
         mDragLayout.addDragCallback(mDragCallback);
 
-        mEvaluator = Evaluator.getInstance(activity);
-
         if (mEvaluator != null) {
             initializeController(isResultLayout);