PRÁTICA 8 – STRINGS XML

Objetivo:

Utilizar o arquivo strings.xml no diretório RES para gerenciar traduções e outras strings

Introdução

Dentro do diretório RES do seu aplicativo há um arquivo xml para todas os textos fixos mostrados, o que simplifica a tradução. Há também um arquivo para cores, estilos e dimensões.

Tarefa:

Usar strings.xml ao invés de hard-codded strings:

Programa 1 – Exemplo de Strings.xml:

<resources>
    <string name="app_name">Empty</string>
    <string name="red">RED</string>
    <string name="orange">ORANGE</string>
    <string name="yellow">YELLOW</string>
    <string name="green">GREEN</string>
    <string name="blue">BLUE</string>
    <string name="indigo">INDIGO</string>
    <string name="violet">VIOLET</string>
</resources>

<string name="app_name">Empty</string>

<string name="orange">ORANGE</string>

<string name="yellow">YELLOW</string>

<string name="green">GREEN</string>

<string name="indigo">INDIGO</string>

<string name="violet">VIOLET</string>

</resources>

Programa 1 – Exemplo de layout que pode ser traduzido:

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

    <TextView
        android:text="@string/red"
        android:id="@+id/TextView01"
        android:layout_height="wrap_content"
        android:background="#f00"
        android:gravity="center"
        android:textColor="#000"
        android:layout_width="wrap_content"
        android:padding="25dp"></TextView>

    <TextView
        android:text="@string/orange"
        android:layout_height="wrap_content"
        android:background="#ffa500"
        android:gravity="center"
        android:textColor="#000"
        android:id="@+id/TextView02"
        android:layout_width="wrap_content"
        android:layout_centerHorizontal="true"
        android:padding="25dp"></TextView>

    <TextView
        android:text="@string/yellow"
        android:layout_height="wrap_content"
        android:background="#ffff00"
        android:gravity="center"
        android:textColor="#000"
        android:id="@+id/TextView03"
        android:layout_width="wrap_content"
        android:layout_alignParentRight="true"
        android:padding="25dp"></TextView>

    <TextView
        android:text="@string/green"
        android:layout_height="wrap_content"
        android:background="#0f0"
        android:gravity="center"
        android:textColor="#000"
        android:id="@+id/TextView04"
        android:layout_width="wrap_content"
        android:layout_toLeftOf="@+id/TextView05"
        android:padding="25dp"
        android:layout_centerVertical="true"></TextView>

    <TextView
        android:text="@string/blue"
        android:layout_height="wrap_content"
        android:background="#00f"
        android:gravity="center"
        android:textColor="#fff"
        android:id="@+id/TextView05"
        android:layout_width="wrap_content"
        android:layout_centerInParent="true"
        android:layout_margin="10dp"
        android:padding="25dp"></TextView>

    <TextView
        android:text="@string/indigo"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textColor="#fff"
        android:id="@+id/TextView06"
        android:layout_width="wrap_content"
        android:layout_toRightOf="@+id/TextView05"
        android:background="#4b0082"
        android:padding="25dp"
        android:layout_centerVertical="true"></TextView>

    <TextView
        android:text="@string/violet"
        android:layout_height="wrap_content"
        android:background="#ee82ee"
        android:gravity="center"
        android:textColor="#000"
        android:id="@+id/TextView07"
        android:layout_alignParentBottom="true"
        android:layout_width="fill_parent"
        android:padding="25dp"></TextView>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_height="fill_parent"

android:layout_width="fill_parent">

<TextView

android:text="@string/red"

android:id="@+id/TextView01"

android:layout_height="wrap_content"

android:background="#f00"

android:gravity="center"

android:textColor="#000"

android:layout_width="wrap_content"

android:padding="25dp"></TextView>

<TextView

android:text="@string/orange"

android:layout_height="wrap_content"

android:background="#ffa500"

android:gravity="center"

android:textColor="#000"

android:id="@+id/TextView02"

android:layout_width="wrap_content"

android:layout_centerHorizontal="true"

android:padding="25dp"></TextView>

<TextView

android:text="@string/yellow"

android:layout_height="wrap_content"

android:background="#ffff00"

android:gravity="center"

android:textColor="#000"

android:id="@+id/TextView03"

android:layout_width="wrap_content"

android:layout_alignParentRight="true"

android:padding="25dp"></TextView>

<TextView

android:text="@string/green"

android:layout_height="wrap_content"

android:background="#0f0"

android:gravity="center"

android:textColor="#000"

android:id="@+id/TextView04"

android:layout_width="wrap_content"

android:layout_toLeftOf="@+id/TextView05"

android:padding="25dp"

android:layout_centerVertical="true"></TextView>

<TextView

android:text="@string/blue"

android:layout_height="wrap_content"

android:background="#00f"

android:gravity="center"

android:textColor="#fff"

android:id="@+id/TextView05"

android:layout_width="wrap_content"

android:layout_centerInParent="true"

android:layout_margin="10dp"

android:padding="25dp"></TextView>

<TextView

android:text="@string/indigo"

android:layout_height="wrap_content"

android:gravity="center"

android:textColor="#fff"

android:id="@+id/TextView06"

android:layout_width="wrap_content"

android:layout_toRightOf="@+id/TextView05"

android:background="#4b0082"

android:padding="25dp"

android:layout_centerVertical="true"></TextView>

<TextView

android:text="@string/violet"

android:layout_height="wrap_content"

android:background="#ee82ee"

android:gravity="center"

android:textColor="#000"

android:id="@+id/TextView07"

android:layout_alignParentBottom="true"

android:layout_width="fill_parent"

android:padding="25dp"></TextView>

</RelativeLayout>

Programa 1 – Crie um novo locale em “open editor” e depois “add Locale”. Adicione portuguese (pt) e coloque os dados abaixo.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">Empty</string>
    <string name="red">VERMELHO</string>
    <string name="orange">LARANJA</string>
    <string name="yellow">AMARELO</string>
    <string name="green">VERDE</string>
    <string name="blue">AZUL</string>
    <string name="indigo">INDIGO</string>
    <string name="violet">VIOLETA</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>

<string name="app_name">Empty</string>

<string name="red">VERMELHO</string>

<string name="orange">LARANJA</string>

<string name="yellow">AMARELO</string>

<string name="green">VERDE</string>

<string name="indigo">INDIGO</string>

<string name="violet">VIOLETA</string>

</resources>

Programa 2 – LayOut pronto para ser traduzido:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="empty.ammsoft.empty.MainActivity"
    android:id="@+id/layout"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="@string/equa_o_de_segundo_grau"
        android:id="@+id/textView4"
        android:layout_gravity="center_horizontal" />

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="a"
            android:id="@+id/textView" />

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/a"
            android:layout_weight="1"
            android:inputType="number|numberSigned" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="b"
            android:id="@+id/textView3" />

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/b"
            android:layout_weight="1"
            android:inputType="number|numberSigned" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="c"
            android:id="@+id/textView2" />

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/c"
            android:layout_weight="1"
            android:inputType="number|numberSigned" />

    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="X1="
            android:id="@+id/x1"
            android:layout_weight="1" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="X2="
            android:id="@+id/x2"
            android:layout_weight="1" />

    </LinearLayout>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:text="@string/resolver"
        android:id="@+id/button2"
        android:layout_weight="1"
        android:layout_gravity="right"
        android:clickable="true"
        android:onClick="calculaSegundoGrau" />

</LinearLayout>

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<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="empty.ammsoft.empty.MainActivity"

android:id="@+id/layout"

android:orientation="vertical">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="@string/equa_o_de_segundo_grau"

android:id="@+id/textView4"

android:layout_gravity="center_horizontal" />

<LinearLayout

android:orientation="horizontal"

android:layout_width="match_parent"

android:layout_height="wrap_content">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceMedium"

android:text="a"

android:id="@+id/textView" />

<EditText

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/a"

android:layout_weight="1"

android:inputType="number|numberSigned" />

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceMedium"

android:text="b"

android:id="@+id/textView3" />

<EditText

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/b"

android:layout_weight="1"

android:inputType="number|numberSigned" />

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceMedium"

android:text="c"

android:id="@+id/textView2" />

<EditText

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/c"

android:layout_weight="1"

android:inputType="number|numberSigned" />

</LinearLayout>

<LinearLayout

android:orientation="horizontal"

android:layout_width="match_parent"

android:layout_height="wrap_content">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="X1="

android:id="@+id/x1"

android:layout_weight="1" />

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="X2="

android:id="@+id/x2"

android:layout_weight="1" />

</LinearLayout>

<Button

android:layout_width="wrap_content"

android:layout_height="match_parent"

android:text="@string/resolver"

android:id="@+id/button2"

android:layout_weight="1"

android:layout_gravity="right"

android:clickable="true"

android:onClick="calculaSegundoGrau" />

</LinearLayout>

Programa 2 – Usando strings XML dentro do programa:

package nome do seu pacote! // Esta linha deve ser mantida com o nome do pacote!

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void calculaSegundoGrau(View v) {
        EditText a_edit = (EditText) findViewById(R.id.a);
        EditText b_edit = (EditText) findViewById(R.id.b);
        EditText c_edit = (EditText) findViewById(R.id.c);
        TextView x1_text = (TextView) findViewById(R.id.x1);
        TextView x2_text = (TextView) findViewById(R.id.x2);

        double a = Double.parseDouble(a_edit.getText().toString());
        double b = Double.parseDouble(b_edit.getText().toString());
        double c = Double.parseDouble(c_edit.getText().toString());

        double delta = b * b - 4*a*c;

        double x1 = -b + Math.sqrt(delta);
        double x2 = -b - Math.sqrt(delta);

        x1_text.setText(getResources().getString(R.string.raiz_x1) + " " + String.valueOf(x1));
        x2_text.setText(getResources().getString(R.string.raiz_x2) + " " + String.valueOf(x2));
    }
}

package nome do seu pacote! // Esta linha deve ser mantida com o nome do pacote!

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.EditText;

import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

}

public void calculaSegundoGrau(View v) {

EditText a_edit = (EditText) findViewById(R.id.a);

EditText b_edit = (EditText) findViewById(R.id.b);

EditText c_edit = (EditText) findViewById(R.id.c);

TextView x1_text = (TextView) findViewById(R.id.x1);

TextView x2_text = (TextView) findViewById(R.id.x2);

double a = Double.parseDouble(a_edit.getText().toString());

double b = Double.parseDouble(b_edit.getText().toString());

double c = Double.parseDouble(c_edit.getText().toString());

double delta = b * b - 4*a*c;

double x1 = -b + Math.sqrt(delta);

double x2 = -b - Math.sqrt(delta);

x1_text.setText(getResources().getString(R.string.raiz_x1) + " " + String.valueOf(x1));

x2_text.setText(getResources().getString(R.string.raiz_x2) + " " + String.valueOf(x2));

}

Programa 2 – Strings.xml com o texto

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">Equação do Segundo Grau</string>
    <string name="eq_de_segundo_grau">Equação de Segundo Grau</string>
    <string name="resolver">Resolver</string>
    <string name="raiz_x1">Raiz X1 =</string>
    <string name="raiz_x2">Raiz X2 =</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>

<string name="app_name">Equação do Segundo Grau</string>

<string name="eq_de_segundo_grau">Equação de Segundo Grau</string>

<string name="resolver">Resolver</string>

</resources>

Desafio: Adicione mensagem de erro indicando que está faltando algum dado ou quando DELTA for menor que zero. Traduza para o inglês e português:

package nome do seu pacote! // Esta linha deve ser mantida com o nome do pacote!

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void calculaSegundoGrau(View v) {
        EditText a_edit = (EditText) findViewById(R.id.a);
        EditText b_edit = (EditText) findViewById(R.id.b);
        EditText c_edit = (EditText) findViewById(R.id.c);
        TextView x1_text = (TextView) findViewById(R.id.x1);
        TextView x2_text = (TextView) findViewById(R.id.x2);

        x1_text.setText(getResources().getString(R.string.raiz_x1));
        x2_text.setText(getResources().getString(R.string.raiz_x2));

        if (a_edit.getText().length() == 0) {
            Toast.makeText(this, getResources().getString(R.string.noA),Toast.LENGTH_SHORT).show();
            return;
        }

        if (b_edit.getText().length() == 0) {
            Toast.makeText(this, getResources().getString(R.string.noB),Toast.LENGTH_SHORT).show();
            return;
        }

        if (c_edit.getText().length() == 0) {
            Toast.makeText(this, getResources().getString(R.string.noC),Toast.LENGTH_SHORT).show();
            return;
        }

        double a = Double.parseDouble(a_edit.getText().toString());
        double b = Double.parseDouble(b_edit.getText().toString());
        double c = Double.parseDouble(c_edit.getText().toString());

        double delta = b * b - 4*a*c;

        if (delta < 0) {
            Toast.makeText(this, getResources().getString(R.string.noReal),Toast.LENGTH_SHORT).show();
            return;
        }

        double x1 = -b + Math.sqrt(delta);
        double x2 = -b - Math.sqrt(delta);

        x1_text.setText(getResources().getString(R.string.raiz_x1) + String.valueOf(x1));
        x2_text.setText(getResources().getString(R.string.raiz_x1) + String.valueOf(x2));
    }
}

package nome do seu pacote! // Esta linha deve ser mantida com o nome do pacote!

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

}

public void calculaSegundoGrau(View v) {

EditText a_edit = (EditText) findViewById(R.id.a);

EditText b_edit = (EditText) findViewById(R.id.b);

EditText c_edit = (EditText) findViewById(R.id.c);

TextView x1_text = (TextView) findViewById(R.id.x1);

TextView x2_text = (TextView) findViewById(R.id.x2);

x1_text.setText(getResources().getString(R.string.raiz_x1));

x2_text.setText(getResources().getString(R.string.raiz_x2));

if (a_edit.getText().length() == 0) {

Toast.makeText(this, getResources().getString(R.string.noA),Toast.LENGTH_SHORT).show();

return;

}

if (b_edit.getText().length() == 0) {

Toast.makeText(this, getResources().getString(R.string.noB),Toast.LENGTH_SHORT).show();

return;

}

if (c_edit.getText().length() == 0) {

Toast.makeText(this, getResources().getString(R.string.noC),Toast.LENGTH_SHORT).show();

return;

}

double a = Double.parseDouble(a_edit.getText().toString());

double b = Double.parseDouble(b_edit.getText().toString());

double c = Double.parseDouble(c_edit.getText().toString());

double delta = b * b - 4*a*c;

if (delta < 0) {

Toast.makeText(this, getResources().getString(R.string.noReal),Toast.LENGTH_SHORT).show();

return;

}

double x1 = -b + Math.sqrt(delta);

double x2 = -b - Math.sqrt(delta);

x1_text.setText(getResources().getString(R.string.raiz_x1) + String.valueOf(x1));

x2_text.setText(getResources().getString(R.string.raiz_x1) + String.valueOf(x2));

}

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">Second Degree Equation</string>
    <string name="eq_de_segundo_grau">Second Degree Equation</string>
    <string name="resolver">Solve</string>
    <string name="raiz_x1">Root X1 =</string>
    <string name="raiz_x2">Root X2 =</string>
    <string name="noA">No value on a!</string>
    <string name="noB">No value on b!</string>
    <string name="noC">No value on c!</string>
    <string name="noReal">Delta lower than ZERO!</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>

<string name="app_name">Second Degree Equation</string>

<string name="eq_de_segundo_grau">Second Degree Equation</string>

<string name="resolver">Solve</string>

<string name="noA">No value on a!</string>

<string name="noB">No value on b!</string>

<string name="noC">No value on c!</string>

<string name="noReal">Delta lower than ZERO!</string>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">Equação do Segundo Grau</string>
    <string name="eq_de_segundo_grau">Equação de Segundo Grau</string>
    <string name="resolver">Resolver</string>
    <string name="raiz_x1">Raiz X1 =</string>
    <string name="raiz_x2">Raiz X2 =</string>
    <string name="noA">Esqueceu o valor de a!</string>
    <string name="noB">Esqueceu o valor de b!</string>
    <string name="noC">Esqueceu o valor de c!</string>
    <string name="noReal">Delta menor que ZERO!</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>

<string name="app_name">Equação do Segundo Grau</string>

<string name="eq_de_segundo_grau">Equação de Segundo Grau</string>

<string name="resolver">Resolver</string>

<string name="noA">Esqueceu o valor de a!</string>

<string name="noB">Esqueceu o valor de b!</string>

<string name="noC">Esqueceu o valor de c!</string>

<string name="noReal">Delta menor que ZERO!</string>

</resources>