diff --git a/java/2-3-widgets/WidgetDemo.java b/java/2-3-widgets/WidgetDemo.java
new file mode 100644
index 0000000000000000000000000000000000000000..32a516cffa321dd011adb25bf65ce38c0dd9996f
--- /dev/null
+++ b/java/2-3-widgets/WidgetDemo.java
@@ -0,0 +1,115 @@
+import java.awt.*;
+import java.awt.event.*;
+import javax.swing.*;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+
+public class WidgetDemo {
+
+ public static void main(String[] args) {
+ WidgetDemo demo = new WidgetDemo();
+ }
+
+ JLabel label;
+
+ WidgetDemo()
+ {
+ JFrame f = new JFrame("WidgetDemo.java");
+ f.setSize(500, 200);
+ f.addWindowListener(new WindowAdapter() {
+ public void windowClosing(WindowEvent e) {
+ System.exit(0);
+ }
+ });
+
+ // create a button and add a listener for events
+ JButton button = new JButton("My Button");
+ button.addActionListener(new ActionListener() {
+ public void actionPerformed(ActionEvent e) {
+ label.setText("button");
+ }
+ });
+
+ // create a slider
+ JSlider slider = new JSlider(0, 100, 50);
+ slider.addChangeListener(new ChangeListener() {
+ public void stateChanged(ChangeEvent e) {
+ JSlider s = (JSlider)e.getSource();
+ label.setText("slider " + s.getValue());
+ }
+ });
+
+ // create a radio button group
+ ButtonGroup radiobuttons = new ButtonGroup();
+ JPanel radioPanel = new JPanel(new GridLayout(1, 0));
+ for (String s: new String[] {"A", "B", "C"})
+ {
+ JRadioButton rb = new JRadioButton(s);
+ rb.addActionListener(radioButtonListener);
+ radiobuttons.add(rb);
+ radioPanel.add(rb);
+ }
+
+ // create a menu
+ JMenu menu = new JMenu("Choices");
+ // create some menu choices
+ for (String s: new String[] {"apple", "orange", "banana", "pear" })
+ {
+ // add this menu item to the menu
+ JMenuItem mi = new JMenuItem(s);
+ // set the listener when events occur
+ mi.addActionListener(menuItemListener);
+ // add this menu item to the menu
+ menu.add(mi);
+ }
+ JMenuBar menubar = new JMenuBar();
+ menubar.add(menu);
+
+ // create a label
+ // (we'll use this to display messages)
+ label = new JLabel("message");
+ // set some properties to customize how it looks
+ label.setPreferredSize(new Dimension(500, 60));
+ label.setHorizontalAlignment( SwingConstants.CENTER );
+ label.setBackground(Color.WHITE);
+ label.setBorder(BorderFactory.createLineBorder(Color.black));
+ label.setFont(new Font("SansSerif", Font.PLAIN, 30));
+
+
+ // define the layout
+ // http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html
+
+
+ // add the widgets
+ f.add(button);
+ f.add(slider);
+ f.add(menubar);
+ f.add(radioPanel);
+ f.add(label);
+
+ f.setLayout(new FlowLayout());
+
+ f.setVisible(true);
+ }
+
+ // create a menu item listener
+ MenuItemListener menuItemListener = new MenuItemListener();
+
+ class MenuItemListener implements ActionListener {
+ public void actionPerformed(ActionEvent e) {
+ JMenuItem mi = (JMenuItem)e.getSource();
+ label.setText(mi.getText());
+ }
+ }
+
+ // create a radio button listener
+ RadioButtonListener radioButtonListener = new RadioButtonListener();
+
+ class RadioButtonListener implements ActionListener {
+ public void actionPerformed(ActionEvent e) {
+ JRadioButton rb = (JRadioButton)e.getSource();
+ label.setText(rb.getText());
+ }
+ }
+
+}
diff --git a/java/2-3-widgets/makefile b/java/2-3-widgets/makefile
new file mode 100644
index 0000000000000000000000000000000000000000..dcea5ae9efc87a545872d413dc3fba0f2c6dd814
--- /dev/null
+++ b/java/2-3-widgets/makefile
@@ -0,0 +1,15 @@
+# super simple makefile
+# call it using 'make NAME=name_of_code_file_without_extension'
+# (assumes a .java extension)
+NAME = "WidgetDemo"
+
+all:
+ @echo "Compiling..."
+ javac $(NAME).java
+
+run: all
+ @echo "Running..."
+ java $(NAME)
+
+clean:
+ rm -rf *.class
diff --git a/x/2-3-widgets/button.cpp b/x/2-3-widgets/button.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5962e72fb015ba9bcbf3dd717da94a6185c11dbd
--- /dev/null
+++ b/x/2-3-widgets/button.cpp
@@ -0,0 +1,257 @@
+/*
+CS 349 Code Examples: X Windows and XLib
+
+ button.cpp Implement a ToggleButton UI Widget
+
+- - - - - - - - - - - - - - - - - - - - - -
+
+See associated makefile for compiling instructions
+
+*/
+
+#include <cstdlib>
+
+#include <unistd.h>
+#include <sys/time.h>
+#include <math.h>
+
+#include <iostream>
+#include <sstream>
+#include <list>
+#include <vector>
+
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+
+
+// get microseconds
+unsigned long now() {
+ timeval tv;
+ gettimeofday(&tv, NULL);
+ return tv.tv_sec * 1000000 + tv.tv_usec;
+}
+
+
+using namespace std;
+
+
+// - - - X globals - - -
+
+struct XInfo {
+ Display* display;
+ Window window;
+ int screen;
+ GC gc;
+};
+
+XInfo xinfo;
+
+// frames per second to run animation loop
+int FPS = 60;
+
+// helper function to set X foreground colour
+enum Colour {BLACK, WHITE};
+void setForeground(Colour c) {
+ if (c == BLACK) {
+ XSetForeground(xinfo.display, xinfo.gc, BlackPixel(xinfo.display, xinfo.screen));
+ } else {
+ XSetForeground(xinfo.display, xinfo.gc, WhitePixel(xinfo.display, xinfo.screen));
+ }
+}
+
+
+// isPaused functionality
+bool isPaused = false;
+// isPaused callback (a simple event handler)
+void togglePause(bool isOn) {
+ isPaused = isOn;
+}
+
+// A toggle button widget
+class ToggleButton {
+
+public:
+
+ ToggleButton(int _x, int _y, void (*_toggleEvent)(bool)) {
+ x = _x;
+ y = _y;
+ toggleEvent = _toggleEvent;
+ isOn = false;
+ diameter = 50;
+ }
+
+ // the CONTROLLER
+ void mouseClick(int mx, int my) {
+ float dist = sqrt(pow(mx - x, 2) + pow(my - y, 2));
+ if (dist < diameter / 2) {
+ toggle();
+ }
+ }
+
+ // the VIEW
+ void draw() {
+
+ if (isOn) {
+ setForeground(BLACK);
+ XFillArc(xinfo.display, xinfo.window, xinfo.gc,
+ x - diameter / 2,
+ y - diameter / 2,
+ diameter, diameter,
+ 0, 360 * 64);
+ setForeground(WHITE);
+ XDrawArc(xinfo.display, xinfo.window, xinfo.gc,
+ x - diameter / 2,
+ y - diameter / 2,
+ diameter, diameter,
+ 0, 360 * 64);
+ } else {
+ setForeground(WHITE);
+ XFillArc(xinfo.display, xinfo.window, xinfo.gc,
+ x - diameter / 2,
+ y - diameter / 2,
+ diameter, diameter,
+ 0, 360 * 64);
+ setForeground(BLACK);
+ XDrawArc(xinfo.display, xinfo.window, xinfo.gc,
+ x - diameter / 2,
+ y - diameter / 2,
+ diameter, diameter,
+ 0, 360 * 64);
+ }
+ }
+
+private:
+
+ // VIEW "essential geometry"
+ int x;
+ int y;
+ int diameter;
+
+ // toggle event callback
+ void (*toggleEvent)(bool);
+
+ // the MODEL
+ bool isOn;
+
+ void toggle() {
+ isOn = !isOn;
+ toggleEvent(isOn);
+ }
+};
+
+
+int main( int argc, char *argv[] ) {
+
+ xinfo.display = XOpenDisplay("");
+ if (xinfo.display == NULL) exit (-1);
+ int screennum = DefaultScreen(xinfo.display);
+ long background = WhitePixel(xinfo.display, screennum);
+ long foreground = BlackPixel(xinfo.display, screennum);
+ xinfo.window = XCreateSimpleWindow(xinfo.display, DefaultRootWindow(xinfo.display),
+ 10, 10, 300, 200, 2, foreground, background);
+ XSelectInput(xinfo.display, xinfo.window,
+ ButtonPressMask | KeyPressMask); // select events
+ XMapRaised(xinfo.display, xinfo.window);
+ XFlush(xinfo.display);
+
+ XEvent event; // save the event here
+
+ // ball postition, size, and velocity
+ XPoint ballPos;
+ ballPos.x = 50;
+ ballPos.y = 50;
+ int ballSize = 50;
+ XPoint ballDir;
+ ballDir.x = 3;
+ ballDir.y = 3;
+
+ // create gc for drawing
+ xinfo.gc = XCreateGC(xinfo.display, xinfo.window, 0, 0);
+
+ // time of last xinfo.window paint
+ unsigned long lastRepaint = 0;
+
+ XWindowAttributes w;
+ XGetWindowAttributes(xinfo.display, xinfo.window, &w);
+
+ ToggleButton toggleButton(150, 100, &togglePause);
+
+ // event loop
+ while ( true ) {
+
+ // TRY THIS
+ // comment out this conditional to see what happens when
+ // events block (run the program and keep pressing the mouse)
+ if (XPending(xinfo.display) > 0) {
+ XNextEvent( xinfo.display, &event );
+
+ switch ( event.type ) {
+
+ // mouse button press
+ case ButtonPress:
+ // cout << "ButtonPress" << endl;
+ toggleButton.mouseClick(event.xbutton.x, event.xbutton.y);
+ break;
+
+ case KeyPress: // any keypress
+ KeySym key;
+ char text[10];
+ int i = XLookupString( (XKeyEvent*)&event, text, 10, &key, 0 );
+ if ( i == 1 && text[0] == 'q' ) {
+ XCloseDisplay(xinfo.display);
+ exit(0);
+ }
+ break;
+ }
+ }
+
+ unsigned long end = now();
+
+ if (end - lastRepaint > 1000000 / FPS) {
+
+
+ // clear background
+ XClearWindow(xinfo.display, xinfo.window);
+
+ // draw ball from centre
+ setForeground(BLACK);
+ XFillArc(xinfo.display, xinfo.window, xinfo.gc,
+ ballPos.x - ballSize / 2,
+ ballPos.y - ballSize / 2,
+ ballSize, ballSize,
+ 0, 360 * 64);
+
+
+ if (!isPaused) {
+
+ // update ball position
+ ballPos.x += ballDir.x;
+ ballPos.y += ballDir.y;
+
+ // bounce ball
+ if (ballPos.x + ballSize / 2 > w.width ||
+ ballPos.x - ballSize / 2 < 0)
+ ballDir.x = -ballDir.x;
+ if (ballPos.y + ballSize / 2 > w.height ||
+ ballPos.y - ballSize / 2 < 0)
+ ballDir.y = -ballDir.y;
+
+ }
+
+ toggleButton.draw();
+
+ XFlush( xinfo.display );
+
+ lastRepaint = now(); // remember when the paint happened
+ }
+
+ // IMPORTANT: sleep for a bit to let other processes work
+ if (XPending(xinfo.display) == 0) {
+ usleep(1000000 / FPS - (end - lastRepaint));
+ }
+
+
+ }
+ XCloseDisplay(xinfo.display);
+}
diff --git a/x/2-3-widgets/makefile b/x/2-3-widgets/makefile
new file mode 100644
index 0000000000000000000000000000000000000000..f100361d1b1ace3ad7e1bcd2e896fb19bc4eac7d
--- /dev/null
+++ b/x/2-3-widgets/makefile
@@ -0,0 +1,19 @@
+# super simple makefile
+# call it using 'make NAME=name_of_code_file_without_extension'
+# (assumes a .cpp extension)
+NAME = "button"
+
+# Add $(MAC_OPT) to the compile line for macOS
+# (should be ignored by Linux, set to nothing if causing problems)
+MAC_OPT = -I/opt/X11/include
+
+all:
+ @echo "Compiling..."
+ g++ -o $(NAME) $(NAME).cpp -L/opt/X11/lib -lX11 -lstdc++ $(MAC_OPT)
+
+run: all
+ @echo "Running..."
+ ./$(NAME)
+
+clean:
+ -rm *o