Add calorie per 100g calculator to 'Add a new entry' screen

app/src/main/java/org/secuso/privacyfriendlyfoodtracker/ui/AddFoodFragment.java

@@ -16,15 +16,24 @@
 */
 package org.secuso.privacyfriendlyfoodtracker.ui;
 
+import android.annotation.SuppressLint;
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
 import android.os.Bundle;
+import android.text.Editable;
 import android.text.InputFilter;
 import android.text.InputType;
+import android.text.TextWatcher;
 import android.util.Log;
+import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.EditText;
+import android.widget.LinearLayout;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
@@ -52,6 +61,7 @@ public class AddFoodFragment extends Fragment {
     TextView textView;
     DatabaseFacade databaseFacade;
     EditText amountField;
+    TextInputLayout caloriesFieldLayout;
     EditText caloriesField;
     /**
      * The required empty public constructor
@@ -84,6 +94,7 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container,
         InputFilter[] caloriesFilter = { new InputFilter.LengthFilter(10) };
 
         amountField = parentHolder.findViewById(R.id.input_amount);
+        caloriesFieldLayout = parentHolder.findViewById(R.id.inputCalories);
         caloriesField = parentHolder.findViewById(R.id.input_calories);
         amountField.setFilters(amountFilter);
         amountField.setInputType(InputType.TYPE_CLASS_NUMBER);
@@ -132,6 +143,8 @@ public void setUserVisibleHint(boolean isVisible) {
             nameField.setFocusable(false);
             nameField.setClickable(false);
             nameField.setTextColor(getResources().getColor(R.color.middlegrey));
+            caloriesFieldLayout.setEndIconActivated(false);
+            caloriesFieldLayout.setEndIconMode(TextInputLayout.END_ICON_NONE);
             caloriesField.setText(String.format(Locale.ENGLISH, "%.2f", referenceActivity.calories));
             caloriesField.setFocusable(false);
             caloriesField.setClickable(false);
@@ -144,6 +157,9 @@ public void setUserVisibleHint(boolean isVisible) {
             nameField.setFocusableInTouchMode(true);
             nameField.setClickable(true);
             nameField.setTextColor(getResources().getColor(R.color.black));
+            caloriesFieldLayout.setEndIconActivated(true);
+            caloriesFieldLayout.setEndIconMode(TextInputLayout.END_ICON_CUSTOM);
+            caloriesFieldLayout.setEndIconOnClickListener(caloriesPer100GCalculatorClickListener);
             caloriesField.setText("");
             caloriesField.setFocusable(true);
             caloriesField.setFocusableInTouchMode(true);
@@ -227,4 +243,96 @@ private void showErrorMessage(View view, int errorMessageId){
         }
     }
 
+    private final View.OnClickListener caloriesPer100GCalculatorClickListener = v -> {
+        final Context context = getContext();
+        if (context == null) return;
+
+        final AlertDialog.Builder caloriesPer100GramsCalculatorDialog = new AlertDialog.Builder(context);
+
+        caloriesPer100GramsCalculatorDialog.setTitle(getString(R.string.calculate_kcal_per_100g));
+
+        LinearLayout container = new LinearLayout(context);
+        container.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
+        container.setOrientation(LinearLayout.VERTICAL);
+
+        final EditText calories = new EditText(context);
+        InputFilter[] caloriesInputFilter = new InputFilter[1];
+        caloriesInputFilter[0] = new InputFilter.LengthFilter(5);
+        calories.setFilters(caloriesInputFilter);
+        calories.setInputType(InputType.TYPE_CLASS_NUMBER);
+
+        final TextInputLayout caloriesLayout = new TextInputLayout(context);
+        caloriesLayout.addView(calories);
+        caloriesLayout.setHint(getString(R.string.calories));
+
+        final EditText grams = new EditText(context);
+        InputFilter[] gramsInputFilter = new InputFilter[1];
+        gramsInputFilter[0] = new InputFilter.LengthFilter(5);
+        grams.setFilters(gramsInputFilter);
+        grams.setInputType(InputType.TYPE_CLASS_NUMBER);
+
+        final TextInputLayout gramsLayout = new TextInputLayout(context);
+        gramsLayout.addView(grams);
+        gramsLayout.setHint(getString(R.string.grams));
+
+        final String emptyResult = String.format(getString(R.string.x_equals_n), getString(R.string.hint_food_calories), "~");
+
+        final TextView result = new TextView(context);
+        result.setGravity(Gravity.CENTER_HORIZONTAL);
+        result.setText(emptyResult);
+
+        final TextWatcher textWatcher = new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+
+            }
+
+            @Override
+            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+
+            }
+
+            @Override
+            public void afterTextChanged(Editable editable) {
+                try {
+                    Float caloriesAmount = Float.parseFloat(calories.getText().toString());
+                    Float gramsAmount = Float.parseFloat(grams.getText().toString());
+
+                    float caloriesPer100G = (caloriesAmount / gramsAmount) * 100;
+
+                    if (!Float.isNaN(caloriesPer100G) && !Float.isInfinite(caloriesPer100G)) {
+
+                        result.setText(String.format(getString(R.string.x_equals_n), getString(R.string.hint_food_calories), Float.toString(caloriesPer100G)));
+                        result.setTag(R.id.tag_calories_per_calculator_result, caloriesPer100G);
+                        return;
+                    }
+                } catch (NumberFormatException e) {
+                    // no-op
+                }
+
+                result.setText(emptyResult);
+            }
+        };
+
+        calories.addTextChangedListener(textWatcher);
+        grams.addTextChangedListener(textWatcher);
+
+        container.addView(caloriesLayout);
+        container.addView(gramsLayout);
+        container.addView(result);
+
+        caloriesPer100GramsCalculatorDialog.setView(container);
+
+        caloriesPer100GramsCalculatorDialog.setPositiveButton(getResources().getString(R.string.save), (dialogInterface, i) -> {
+            Object tag = result.getTag(R.id.tag_calories_per_calculator_result);
+            if (tag instanceof Float) {
+                caloriesField.setText(Float.toString((float) tag));
+            }
+        });
+
+        caloriesPer100GramsCalculatorDialog.setNegativeButton(getResources().getString(R.string.decline), (dialog, whichButton) -> {});
+
+        caloriesPer100GramsCalculatorDialog.show();
+    };
+
 }

app/src/main/res/drawable/ic_calculate_24dp.xml

@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#000000"
+    android:viewportHeight="24" android:viewportWidth="24"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="@android:color/white" android:pathData="M19,3H5C3.9,3 3,3.9 3,5v14c0,1.1 0.9,2 2,2h14c1.1,0 2,-0.9 2,-2V5C21,3.9 20.1,3 19,3zM13.03,7.06L14.09,6l1.41,1.41L16.91,6l1.06,1.06l-1.41,1.41l1.41,1.41l-1.06,1.06L15.5,9.54l-1.41,1.41l-1.06,-1.06l1.41,-1.41L13.03,7.06zM6.25,7.72h5v1.5h-5V7.72zM11.5,16h-2v2H8v-2H6v-1.5h2v-2h1.5v2h2V16zM18,17.25h-5v-1.5h5V17.25zM18,14.75h-5v-1.5h5V14.75z"/>
+</vector>

app/src/main/res/layout/content_food.xml

@@ -57,6 +57,8 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             app:errorEnabled="true"
+            app:endIconMode="custom"
+            app:endIconDrawable="@drawable/ic_calculate_24dp"
             app:layout_constraintTop_toBottomOf="@+id/inputFoodAmount">
 
             <EditText

app/src/main/res/values-de/strings.xml

@@ -83,6 +83,10 @@
     <string name="action_confirm">Bestätigen</string>
     <string name="action_cancel">Abbrechen</string>
     <string name="delete_entry_prompt">Löschen?</string>
+    <string name="grams">Gramm</string>
+    <string name="calories">Kalorien</string>
+    <string name="x_equals_n">%1$s = %2$s</string>
+    <string name="calculate_kcal_per_100g">Berechnung kCal/100g</string>
 
     <string name="setup_step_generating_key">Erstelle Key</string>
     <string name="setup_step_generating_passphrase">Erstelle Passphrase</string>

app/src/main/res/values-fr/strings.xml

@@ -72,4 +72,8 @@
     <string name="pref_example_switch">Example Switch</string>
     <string name="pref_example_switch_summary">Example Switch Summary</string>
     <string name="pref_example_summary">Example Summary</string>
+    <string name="grams">Grammes</string>
+    <string name="calories">Calories</string>
+    <string name="x_equals_n">%1$s = %2$s</string>
+    <string name="calculate_kcal_per_100g">Calculer kCal/100g</string>
 </resources>

app/src/main/res/values/ids.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <item type="id" name="tag_calories_per_calculator_result" />
+</resources>

app/src/main/res/values/strings.xml

@@ -86,6 +86,10 @@
     <string name="action_confirm">Confirm</string>
     <string name="action_cancel">Cancel</string>
     <string name="delete_entry_prompt">Delete?</string>
+    <string name="grams">Grams</string>
+    <string name="calories">Calories</string>
+    <string name="x_equals_n">%1$s = %2$s</string>
+    <string name="calculate_kcal_per_100g">Calculate kCal/100g</string>
 
 
     <string name="setup_step_generating_key">Generating Key</string>