Question

Develop a temperature converter GUI JavaFX application that consists of two labels and two text fields. Typing a temperature into the Celsius field and then pressing the "Enter" key causes the equivalent Fahrenheit temperature to appear in the Fahrenheit field and vice versa.

O® Temperature Converter Celsius 100 Fahrenheit 212.0

Typing a non-numeric value into either field causes the following error dialog to appear:

Formulas are simple:Celsius to Fahrenheit° F = 9/5 ( ° C) + 32Fahrenheit to Celsius° C = 5/9 (° F - 32).

Answer 1

Answer:

import javafx.application.Application; import javafx.event.ActionEvent; import javafx.geometry.Insets; import javafx.scene.Scene; import javafx.scene.control.*; import javafx.scene.control.Alert.AlertType; import javafx.scene.layout.GridPane; import javafx.stage.Stage; public class TemperatureConverter extends Application{ //Required scene variable Scene Window; //Required variables double celsius = 0.00,fahrenheit = 0.00;    //Main method() public static void main(String[] args){ launch(args); } //Method to execute on pressing enter public static double onEnter(ActionEvent e,String s,double input){ //Required variable double result = 0; //If the string is "celsius" if(s.compareToIgnoreCase("celsius") == 0){ //Calculates fahrenheit value of the input result = (((9*input)/5) + 32); }    else if(s.compareToIgnoreCase("fahrenheit") == 0){ //Else if the input is "fahrenheit" //Calculates celsius of the input result = (5*(input - 32))/9; } //Returns result return result; }    //Start method @Override public void start(Stage primaryStage) throws Exception { //Set title for the Stage object primaryStage.setTitle("Temperature Converter");    //Required components of the GUI and their styings Label celsiusLbl = new Label("Celcius "); celsiusLbl.setPadding(new Insets(0,0,0,10)); celsiusLbl.setStyle("-fx-font-weight: bold"); Label fahrenheitLbl = new Label("Fahrenheit "); fahrenheitLbl.setStyle("-fx-font-weight: bold");    TextField celsiusTxt = new TextField(); TextField fahrenheitTxt = new TextField(); //Binding event for first textbox celsiusTxt.setOnAction((ActionEvent e)->{    //Read text from first text box to string 'input' String input = celsiusTxt.getText(); //To handle exception try{ //If input is not null if(input.compareTo("") !=0) //Parse input to double celsius = Double.parseDouble(input); //Call onEnter method and calculate fahrenheit fahrenheit = TemperatureConverter.onEnter(e,"celsius",celsius); //Display fahrenheit in sen=cond textbox fahrenheitTxt.setText(String.valueOf(fahrenheit)); } catch(Exception ex){ //If input is not double then exception will be catched here    //Create object of alert class Alert alert = new Alert(AlertType.INFORMATION); //Display contents in the alert object alert.setHeaderText(null); alert.setTitle("Error"); alert.setContentText("Error, input must be numerical"); alert.showAndWait(); }    });    //Binding event for second textbox fahrenheitTxt.setOnAction((ActionEvent e)->{ //Read text from second text box to string 'input' String input = fahrenheitTxt.getText(); //To handle exception    try{ //If input is not null if(input.compareTo("") != 0) //Parse input to double fahrenheit = Double.parseDouble(input); //Call onEnter method and calculate celsius celsius = TemperatureConverter.onEnter(e,"fahrenheit",fahrenheit); //Display celsius in first textbox celsiusTxt.setText(String.valueOf(celsius)); } catch(Exception ex){ //If input is not double then exception will be catched here    //Create object of alert class Alert alert = new Alert(AlertType.INFORMATION); //Display contents in the alert object alert.setHeaderText(null); alert.setTitle("Error"); alert.setContentText("Error, input must be numerical"); alert.showAndWait(); }       });    //GridPane Object to set components GridPane g = new GridPane(); //Set components in repsective columns g.addColumn(0,celsiusLbl); g.addColumn(1,celsiusTxt); g.addColumn(2,fahrenheitLbl); g.addColumn(3,fahrenheitTxt);    //Set horizontal gap g.setHgap(10);    //Initialize Window Window = new Scene(g,500,50);    //Add Window to stage object primaryStage.setScene(Window); primaryStage.show();    } }

SCREENSHOTS :

Please see the screehsots of the code below for the indentations of the code.

1 2 3 4 5 ç import juvafx.application. Application; import javafx.event. ActionEvent; import javafx.geometry.Insets; import javafx.scene. Scene; import javafx.scene.control.*; import javafx.scene.control.Alert. AlertType; import javafx.scene.layout. GridPane; import javafx. stage. Stage; 6 7 8 9 public class TemperatureConverter extends Application { 10 ll 12 13 14 15 16 17 //Required scene variable Scene Window; // Required variables double celsius = 0.00, fahrenheit = 0.00; CO 마 19 20 21 22 23 24 25 26 27 28 29 30 31 32 //Main method() public static void main(String[] args) { Launch(args); } //Method to execute on pressing enter public static double on Enter (ActionEvent e, String s, double input) { // Required variable double result = 0; //If the string is "celsius" if(s.compare toIgnoreCase("celsius") == 0){ //Calculates fahrenheit value of the input result - (((9* input)/5) + 32); } *) { else if(s.compareToIgnoreCase("fahrenheit") //Else if the input is "fahrenheit" //Calculates celsius of the input

33 34 35 36 result (5*(input - 32))/9; } // Returns result return result; } 38 39 40 1 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 //Start method @Override public void start(Stage primaryStage) throws Exception { // Set title for the Stage object primaryStage.setTitle("Temperature Converter"); //Required components of the GUI and their styings Label celsiusLbl = new Label("Celcius "); celsiusLbl.setPadding(new Insets(0,0,0,10)); celsiusLbl.setStyle("-fx-font-weight: bold"); Label fahrenheitlbl = new Label("Fahrenheit "); fahrenheitlbl.setStyle("-fx-font-weight: bold"); TextField celsiusTxt = new TextField(); TextField fahrenheittxt = new TextField(); //Binding event for first textbox celsiusTxt.setOnAction((ActionEvent e) ->{ //Read text from first text box to string 'input' String input celsiusTxt.getText(); //To handle exception try{ //If input is not null if(input.compareTo("") !=0) //Parse input to double

67 celsius Double.parseDouble(input); 7/Call on Enter method and calculate fahrenheit fahrenheit = TemperatureConverter.onEnter(e,"celsius", celsius); //Display fahrenheit in sen=cond textbox fahrenheittxt.setText(String.valueOf (Fahrenheit)); 68 69 } 70 71 72 73 74 75 catch(Exception ex) { // If input is not double then exception will be catched here // Create object of alert class Alert alert = new Alert (AlertType . INFORMATION); //Display contents in the alert object alert.setHeaderText(null); alert.setTitle("Error"); alert.setContent Text("Error, input must be numerical"); alert.showAndwait(); 76 77 78 79 80 ܢܟ }); 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 //Binding event for second textbox fahrenheittxt.setOnAction((ActionEvent e)->{ //Read text from second text box to string 'input' String input = fahrenheittxt.getText(); //To handle exception try{ //If input is not null if(input.compareTo("") != 0) //Parse input to double fahrenheit = Double.parseDouble(input); //Call on Enter method and calculate celsius celsius TemperatureConverter.onEnter(e,"fahrenheit", fahrenheit);

//Display celsius in first textbox celsiusTxt.setText(String.valueof (celsius)); 98 99 } catch(Exception ex){ // If input is not double then exception will be catched here //Create object of alert class Alert alert = new Alert (Alert Type . INFORMATION); //Display contents in the alert object alert.setHeaderText(null); alert.setTitle("Error"); alert.setContentText("Error, input must be numerical"); alert.showAndWait(); } }); 100 101 102 103 104 105 106 107 108 109 110 ill 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 //GridPane object to set components GridPane g = new GridPane(); // Set components in repsective columns g.addColumn(e, celsiuslbl); g.addColumn(1, celsiusTxt); g.addColumn(2, fahrenheitlbl); g.addColumn(3, fahrenheittxt); // Set horizontal gap g.setHgap(10); //Initialize Window Window = new Scene(g, 500, 50);

- 128 129 130 131 132 133 134 135 // Add Window to stage object primaryStage.setScene (Window); primaryStage.show(); ܝܟ ܢܟ

OUTPUT :

Initial Output

х Temperature Converter Celcius Fahrenheit

If given valid value

х Temperature Converter Celcius 100 Fahrenheit

After clicking "Enter" in first text box

Х Temperature Converter Celcius 100 Fahrenheit 212.0

Similary for Fahrenheit

Temperature Converter - Celcius Fahrenheit 320

Temperature Converter x Celcius 160.0 Fahrenheit 320

If given wrong input

Temperature Converter Celcius abcd Fahrenheit Error X Error input must be numerical .- OK

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