First pass at Video window

src/main/java/com/loomcom/symon/devices/Crtc.java

@@ -0,0 +1,101 @@
+package com.loomcom.symon.devices;
+
+import com.loomcom.symon.exceptions.MemoryAccessException;
+import com.loomcom.symon.exceptions.MemoryRangeException;
+import com.loomcom.symon.ui.CrtPanel;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+
+/**
+ * Simulation of a 6545 CRTC and virtual CRT output.
+ */
+public class Crtc extends Device {
+
+    public static final int CHAR_WIDTH = 8;
+    public static final int CHAR_HEIGHT = 8;
+    public static final int SCAN_LINES = 9;
+    public static final int COLUMNS = 40;
+    public static final int ROWS = 25;
+    public static final int SCALE = 2;
+
+    public static final int REGISTER_SELECT = 0;
+    public static final int REGISTER_WRITE = 1;
+
+    public static String CHAR_ROM_RESOURCE = "/pet.rom";
+
+    private CrtPanel crtPanel;
+    private int currentRegister = 0;
+
+    public Crtc(int deviceAddress, Memory memory, int videoRamStartAddress) throws MemoryRangeException, IOException {
+        super(deviceAddress, 2, "CRTC");
+        this.crtPanel = new CrtPanel(loadCharRom(CHAR_ROM_RESOURCE), memory.getDmaAccess(), COLUMNS, ROWS,
+                                     CHAR_WIDTH, CHAR_HEIGHT,
+                                     SCALE, SCALE, videoRamStartAddress);
+    }
+
+    private byte[] loadCharRom(String resource) throws IOException {
+        BufferedInputStream bis = null;
+        try {
+            bis = new BufferedInputStream(this.getClass().getResourceAsStream(resource));
+            ByteArrayOutputStream bos = new ByteArrayOutputStream();
+            while (bis.available() > 0) {
+                bos.write(bis.read());
+            }
+            bos.flush();
+            bos.close();
+            return bos.toByteArray();
+        } finally {
+            if (bis != null) {
+                bis.close();
+            }
+        }
+    }
+
+    public CrtPanel getCrtPanel() {
+        return crtPanel;
+    }
+
+    @Override
+    public void write(int address, int data) throws MemoryAccessException {
+        switch (address) {
+            case REGISTER_SELECT:
+                setCurrentRegister(data);
+            case REGISTER_WRITE:
+                writeRegisterValue(data);
+            default:
+                throw new MemoryAccessException("No such address.");
+        }
+    }
+
+    @Override
+    public int read(int address) throws MemoryAccessException {
+        switch (address) {
+            case REGISTER_SELECT:
+                return status();
+            case REGISTER_WRITE:
+                return 0;
+            default:
+                throw new MemoryAccessException("No such address.");
+        }
+    }
+
+    @Override
+    public String toString() {
+        return null;
+    }
+
+    private int status() {
+        return 0;
+    }
+
+    private void setCurrentRegister(int registerNumber) {
+        this.currentRegister = registerNumber;
+    }
+
+    private void writeRegisterValue(int data) {
+
+    }
+}