Start poking at a TerminalWidget.

Widgets/TerminalWidget.cpp

@@ -0,0 +1,69 @@
+#include "TerminalWidget.h"
+#include "Painter.h"
+
+TerminalWidget::TerminalWidget(Widget* parent)
+    : Widget(parent)
+{
+    setRect({ 100, 300, columns() * 8, rows() * 8 });
+    m_screen = new CharacterWithAttributes[rows() * columns() * 2]; 
+    for (unsigned row = 0; row < m_rows; ++row) {
+        for (unsigned column = 0; column < m_columns; ++column) {
+            at(row, column).character = ' ';
+            at(row, column).attribute = 0x07;
+        }
+    }
+    onReceive(String("Serenity/OS").toByteBuffer());
+}
+
+TerminalWidget::~TerminalWidget()
+{
+}
+
+CharacterWithAttributes& TerminalWidget::at(unsigned row, unsigned column)
+{
+    ASSERT(m_screen);
+    ASSERT(row < m_rows);
+    ASSERT(column < m_columns);
+    return m_screen[row * columns() + column];
+}
+
+void TerminalWidget::onPaint(PaintEvent&)
+{
+    Painter painter(*this);
+
+    painter.fillRect({ 0, 0, width(), height() }, Color(0, 0, 0));
+
+    char buf[2] = { 0, 0 };
+    for (unsigned row = 0; row < m_rows; ++row) {
+        int y = row * 8;
+        for (unsigned column = 0; column < m_columns; ++column) {
+            int x = column * 8;
+            buf[0] = at(row, column).character;
+            painter.drawText({ x, y, width(), 8 }, buf, Painter::TextAlignment::TopLeft, Color(0xa0, 0xa0, 0xa0));
+        }
+    }
+}
+
+void TerminalWidget::onReceive(const ByteBuffer& buffer)
+{
+    for (unsigned i = 0; i < buffer.size(); ++i) {
+        onReceive(buffer[i]);
+    }
+}
+
+void TerminalWidget::onReceive(byte ch)
+{
+    at(m_cursorRow, m_cursorColumn).character = ch;
+    printf("%2u,%2u -> ", m_cursorRow, m_cursorColumn);
+    if (++m_cursorColumn > m_columns) {
+        m_cursorColumn = 0;
+        if (m_cursorRow < (m_rows - 1)) {
+            ++m_cursorRow;
+        } else {
+            // FIXME: Scroll it!
+            ASSERT_NOT_REACHED();
+        }
+    }
+    printf("%2u,%2u\n", m_cursorRow, m_cursorColumn);
+}
+