C-Programming-Android-App

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;

import android.content.res.AssetManager;
import android.graphics.Color;
import android.graphics.Typeface;
import android.os.Bundle;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.method.ScrollingMovementMethod;
import android.text.style.ForegroundColorSpan;
import android.util.TypedValue;
import android.widget.TextView;
import java.io.IOException;
import java.io.InputStream;

public class MainActivity extends AppCompatActivity {
    TextView tv;
    Typeface face;
    Spannable raw;
    TextView tvOutput;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tvDisplay);
        face = Typeface.createFromAsset(getAssets(), "Fonts/Consolas.ttf");
        tv.setMovementMethod(new ScrollingMovementMethod());
        tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, getResources().getDimension(R.dimen.textsize3));
        tv.setTypeface(face);
        openFile();
        syntaxHighlight();

        tvOutput = (TextView) findViewById(R.id.tvOutputDisplay);
        tvOutput.setMovementMethod(new ScrollingMovementMethod());
        openOutput();
        tvOutput.setTextSize(TypedValue.COMPLEX_UNIT_SP, getResources().getDimension(R.dimen.textsize3));
    }


    private void openFile() {
        // Using AssetManager and InputStream to open file selected by the user.
        Bundle extras = getIntent().getExtras();
       // temp = extras.getString("KEY");
        //loc = extras.getString("LOC");
        final AssetManager am = getAssets();
        try {
            InputStream is = am.open("Programs/" +  "Hello World.c");
            int size = is.available();
            byte[] buffer = new byte[size];
            is.read(buffer);
            is.close();
            String text = new  String(buffer);
            tv.setText(text);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void openOutput() {
        Bundle extras = getIntent().getExtras();
        final AssetManager am = getAssets();
        try {
            InputStream is = am.open("Outputs/" + "Hello World output.txt");
            int size = is.available();
            byte[] buffer = new byte[size];
            is.read(buffer);
            is.close();
            String text = new  String(buffer);
            tvOutput.setText(text);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    private void syntaxHighlight() {

        String [] green = {"#define", "#include<stdio.h>", "#include<conio.h>", "#include<stdlib.h>", "#include<math.h>",
                "#include<graphics.h>", "#include<string.h>", "#include<malloc.h>", "#include<time.h>", "#include<ctype.h>"};
        for(String key: green){
            fontcolor(key, 0xFF458b00);
        }

        doColor();

        String[] purple = {"int", "float", "char", "signed", "long", "double", "NULL", "1", "2", "3", "4", "5", "6", "7", "8", "9", "0"};
        for(String key: purple){
            fontcolor(key, 0xFFc133a4);
        }

        String [] red = {"printf", "scanf", "if", "else", "for", "while", "switch", "case", "break", "default", "goto", "typedef", "struct", "return", "FILE", "exit", "fopen", "fprintf", "fscanf", "fclose", "(", ")"};
        for(String key: red){
            fontcolor(key, 0xFFDD2626);
        }

        String [] orange = {"main()", "getch()", "void"};
        for(String key: orange){
            fontcolor(key, 0xFFee7621);
        }

        printColor();
        commentColor();
    }



    private void fontcolor(String key, int color) {
        raw = new SpannableString(tv.getText());
        int index = TextUtils.indexOf(raw, key);
        while (index >= 0)
        {
            raw.setSpan(new ForegroundColorSpan(color), index, index + key.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            index=TextUtils.indexOf(raw, key, index + key.length());
        }
        tv.setText(raw);
    }

    private void doColor() {
        raw = new SpannableString(tv.getText());
        int index = TextUtils.indexOf(raw, "do");
        while(index >= 0){
            raw.setSpan(new ForegroundColorSpan(Color.parseColor("#DD2626")), index, index + 2, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            index=TextUtils.indexOf(raw, "do", index + 2);
        }
        tv.setText(raw);
    }

    private void printColor() {
        raw = new SpannableString(tv.getText());
        int index1 =TextUtils.indexOf(raw, '"');
        int index2 = TextUtils.indexOf(raw, '"', index1+1);
        while(index1 >= 0){
            raw.setSpan(new ForegroundColorSpan(Color.BLUE), index1, index2+1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            index1 = TextUtils.indexOf(raw, '"', index2+1);
            index2 = TextUtils.indexOf(raw, '"', index1+1);
        }
        tv.setText(raw);
    }

    private void commentColor() {
        raw = new SpannableString(tv.getText());
        int index=TextUtils.indexOf(raw, "*/");
        raw.setSpan(new ForegroundColorSpan(Color.parseColor("#198CFF")), 0, index+2, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        tv.setText(raw);
    }

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <TextView
        android:id="@+id/tvDisplay"
        android:background="#324065"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop = "true"
        android:layout_centerHorizontal = "true"
        />
    <TextView
        android:layout_width = "wrap_content"
        android:layout_height = "wrap_content"
        android:text = "Output:"
        android:id = "@+id/textView"
        android:layout_below = "@+id/tvDisplay"
        android:layout_centerHorizontal = "true"
        android:textColor = "#ff7aff24"
        android:textSize = "30dp" />
    <TextView
        android:id="@+id/tvOutputDisplay"
        android:background="#4CAF50"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop = "46dp"
        android:layout_below = "@+id/tvDisplay"
        android:layout_centerHorizontal = "true"
         />

</RelativeLayout>

res/values/dimens.xml

<resources>

    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>
    <dimen name="textsize3">8sp</dimen>

</resources>


assets/Programs/Hello World.c
/* Simple C Program to print "Hello World!" */
#include<stdio.h>
#include<conio.h>
main()
{
  printf("Hello world!");
  getch();
}


assets/Outputs/Hello World output.txt
Hello World!


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