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Toolkits

Toolkits. Console I/O Vs Toolkits Containers and Components Event Listeners Toolkit Classes Frames Panel TextField Buttons BorderLayout. Console Vs Graphical User Interface. Hand-crafted hierarchical Vs Automatic Linear Window Graphics and Text Vs Text-Only Editing Vs Transcript

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Toolkits

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  1. Toolkits • Console I/O Vs Toolkits • Containers and Components • Event Listeners • Toolkit Classes • Frames • Panel • TextField • Buttons • BorderLayout

  2. Console Vs Graphical User Interface • Hand-crafted hierarchical Vs Automatic Linear Window • Graphics and Text Vs Text-Only • Editing Vs Transcript • User-Driven Vs Program Driven • Point and Click Vs Typing

  3. Implementing Graphical UI • Create the window • React to user input • Display output

  4. Container frame Component view panel control panel x TextField y TextField New Point Button Quit Button Creating Hierarchical Window

  5. AWT Classes Component Container TextField Button Frame Panel

  6. frame view panel control panel x TextField y TextField New Point Button Quit Button Creating Hierarchical Structure Frame frame = new Frame("Points Plotter"); Panel control = new Panel(); frame.add(control); frame.add(new Panel()); control.add(new Button(“New Point”)); control.add(new Button(“Quit”); control.add(new TextField(“0”)); control.add(new TextField(“0”)); frame.setSize ( FRAME_WIDTH, FRAME_HEIGHT) frame.setVisible ( true)

  7. frame view panel control panel x TextField y TextField New Point Button Quit Button Hierarchical Structure Vs Layout

  8. frame view panel control panel x TextField y TextField New Point Button Quit Button Hierarchical Structure Vs Layout

  9. frame view panel control panel x TextField y TextField New Point Button Quit Button Layout Managers BorderLayout GridLayout

  10. North West East Center North South West Center East South BorderLayout frame.setLayout(new BorderLayout()); frame.add( new Panel(), BorderLayout.CENTER); frame.add(new Panel(), BorderLayout.WEST); frame.add(new Panel(), BorderLayout.EAST); frame.add(new Panel(), BorderLayout.NORTH); frame.add(new Panel(), BorderLayout.SOUTH);

  11. GridLayout controller.setLayout(new GridLayout(2,3)); controller.add(new TextField()); controller.add(new TextField()); controller.add(new TextField()); controller.add(new TextField());

  12. Default frame Will use subclasses view panel control panel x TextField y TextField New Point Button Quit Button Laying out Hierarchical Structure Frame frame = new Frame("Points Plotter"); frame.setLayout(new BorderLayout()); Panel control = new Panel(); Frame.add(control); frame.add(control, BorderLayout.WEST); Frame.add(new Panel()); frame.add(new Panel(), BorderLayout.CENTER); control.setLayout(new GridLayout(4, 1 )); control.add(new Button(“New Point”)); control.add(new Button(“Quit”)); control.add(new TextField(“0”)); control.add(new TextField(“0”)); frame.setSize ( FRAME_WIDTH, FRAME_HEIGHT); frame.setVisible ( true);

  13. frame view panel control panel x TextField y TextField New Point Button Quit Button Implementing Graphical UI • Create the window • React to user input • Display output

  14. Listenable Listener New Point Button PointHistoryModel addElement() Reacting to New Point Click NewPoint Listener addActionListener() actionPerformed() Button Clicked newPointButton.addActionListener(newPointListener);

  15. Action Listener Code // import declarations …. publicclass ANewPointActionListener implements ActionListener { PointHistory pointHistory; TextField xField; TextField yField; public ANewPointActionListener (PointHistory thePointHistory, TextField theXField, TextField theYField) { pointHistory = thePointHistory; xField = theXField; yField = theYField; } // Called when the New Point button is pressed. publicvoid actionPerformed(ActionEvent ae) { pointHistory.addElement( Integer.parseInt(xField.getText()), Integer.parseInt(yField.getText())); } }

  16. frame view panel control panel x TextField y TextField New Point Button Quit Button Implementing Graphical UI • Create the window • React to user input • Display output

  17. Panel Resized Panel Uncovered Invoke Graphics Operations View Panel Panel extends Displaying Output paint(Graphics g) repaint() paint(Graphics g)

  18. Graphics Operations • drawLine( int x1, int y1, int x2, int y2 ) • drawString( String s, int x, int y ) • drawRect( int x, int y, int width, int height ) • drawOval( int x, int y, int width, int height ) • fillOval( int x, int y, int width, int height) • setColor(Color newColor)

  19. Drawing Bars publicvoid paint(Graphics g) { drawBars(g); } void drawBars (Graphics g) { if (pointHistory == null) return; finalint BAR_WIDTH = 6; Rectangle myBounds = getBounds(); for (int i = 0; i < pointHistory.size(); i++) { PointModel nextPoint = (PointModel) pointHistory.elementAt(i); g.setColor(java.awt.Color.darkGray); g.fillRect(nextPoint.getX() - BAR_WIDTH, myBounds.height - nextPoint.getY(), BAR_WIDTH, nextPoint.getY()); } }

  20. Implementing Graphical UI • Create the window • Use Frames, LayoutManagers, Panels, Buttons, TextFields • React to user input • Define Listeners that call methods in Model • Display output • Override paint() method • Call graphics operations

  21. Displaying Points All four views displayed concurrently and kept in Sync.

  22. Composer: Single Main Class MVC in a Graphical Application Controller: AConsoleController View: AConsoleView Controller: AnAWTController View: ABarChartView Model: APointHistoryModel Controller: AnAWTController View: APlotterView Controller: ASwingController View: APlotterView

  23. frame Controller: AnAWTController View: ABarChartView view panel control panel Composer: Single Main Class Model: APointHistoryModel Same as x TextField y TextField New Point Button Quit Button Same as MVC in a Graphical Application NewPoint Listener

  24. Panel Resized Panel Uncovered MVC View View Panel Panel Model updated View Panel  View paint(Graphics g) repaint() Invoke Graphics Operations extends paint(Graphics g) pointHostoryUpdated()

  25. View import java.awt.Rectangle; import shapes.PointModel; public class APointHistoryBarChart extends Panel implements PointHistoryListener { PointHistory pointHistory; public void pointHistoryUpdated(PointHistory thePointHistory) { pointHistory = thePointHistory; repaint(); } // Called by repaint and other methods that refresh the view. public void paint(Graphics g) { drawBars(g); }

  26. View (contd) void drawBars (Graphics g) { if (pointHistory == null) return; final int BAR_WIDTH = 6; Rectangle myBounds = this.getBounds(); for (int i = 0; i < pointHistory.size(); i++) { PointModel nextPoint = (PointModel) pointHistory.elementAt(i); g.setColor(java.awt.Color.darkGray); g.fillRect(nextPoint.getX() - BAR_WIDTH, myBounds.height - nextPoint.getY(), BAR_WIDTH, nextPoint.getY()); } } }

  27. MVC Controller Panel Panel  Controller • Create control components (text fields, buttons) • Add components • Create component listeners • Register listeners with components. extends Constructor

  28. import java.awt.GridLayout; import java.awt.Button; import java.awt.TextField; import java.awt.event.ActionListener; public class APointHistoryAWTController extends Panel { int numComponents = 0; PointHistory pointHistory ; public APointHistoryAWTController (PointHistory thePointHistory) { pointHistory = thePointHistory; createComponents (); setLayout(new GridLayout(numComponents,1)); } void createComponents() { TextField xField = createTextField(“0”); add(xField); TextField yField = createTextField(“0”); add(yField); add (createButton ("New Point", new ANewPointActionListener(pointHistory, xField, yField))); add (createButton ("Quit", new AQuitActionListener())); } Controller

  29. Controller (contd) Button createButton(String name, ActionListener listener) { Button button = new Button(name); button.addActionListener(listener); numComponents++; return button; } TextField createTextField(String text) { TextField field = new TextField(text); field.setEditable(true); numComponents++; return field; } }

  30. Composer: Single Main Class Composer main() • Create frame • Set its layout manager • Create model, view(s) and controller(s) • Make views listener of model • Add views and controllers to frame • Set frame size • Make frame visible • Set frame location

  31. 2 Barchart Composer • publicclass APointHistoryBarchartComposer { • staticfinalint FRAME_WIDTH = 300; • staticfinalint FRAME_HEIGHT = 300; • publicstaticvoid main (String args[]) { • PointHistoryModel pointHistoryModel = new APointHistoryModel(); • createBarChartEditor(pointHistoryModel); • createBarChartEditor(pointHistoryModel); • } • publicstaticvoid createBarChartEditor (PointHistoryModel pointHistoryModel) { • Frame frame = new Frame("Points Bar Chart"); • frame.add (createAWTController(pointHistoryModel), • BorderLayout.WEST); • frame.add (createBarChart(pointHistoryModel), BorderLayout.CENTER); // important to set this, default seems to be (0,0) • frame.setSize (FRAME_WIDTH, FRAME_HEIGHT); • setLocation (frame); • // important to make frame visible, default is invisible • frame.setVisible(true); • }

  32. Barchart Composer (contd) publicstatic APointHistoryBarChart createBarChart(PointHistoryModel pointHistoryModel) { APointHistoryBarChart pointHistoryView = new APointHistoryBarChart(); // make view an eavesdropper of model pointHistoryModel.addListener(pointHistoryView); return pointHistoryView; } publicstatic APointHistoryAWTController createAWTController(PointHistory pointHistory) { returnnew APointHistoryAWTController(pointHistory); }

  33. Barchart Composer (contd) staticint curX = 0; staticint curY = 0; staticfinalint X_OFFSET = 100; staticfinalint Y_OFFSET = 100; staticvoid setLocation (Frame frame) { frame.setLocation (curX, curY); curX += X_OFFSET; curY += Y_OFFSET; } }

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