Diff: kbd_mgr/KeyboardState.h

Revision:

2:eb4cc53ff33d

Child:

3:1310c57aca77

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kbd_mgr/KeyboardState.h	Sun Jan 23 23:15:36 2011 +0000
@@ -0,0 +1,94 @@
+#ifndef KEYBOARD_STATE_H_
+#define KEYBOARD_STATE_H_
+
+#include <vector>
+#include <iostream>
+
+namespace kbd_mgr {
+
+/**
+ * @brief A class to hold the state of a keyboard.
+ * A keyboard is handled as a set of key rows. Each row can have as many keys as there are bits in integers.
+ * The class maintains an array of integers to handle the number of rows.
+ * If possible, multiple rows are combined in a single integer to reduce memory footprint.
+ */
+class KeyboardState {
+public:
+    /**
+     * @brief Constructor for a 0x0 keyboard state.
+     */
+    KeyboardState();
+    
+    /**
+     * @brief Constructor for a NxM keyboard state.
+     * @param numRows       Number of key rows (unlimited)
+     * @param numKeysPerRow Number of keys per row (limited to the number of bits in an integer).
+     */
+    KeyboardState(std::size_t numRows, std::size_t numKeysPerRow);
+
+    std::size_t getNumRows() const { return this->numRows; }
+    std::size_t getNumKeysPerRow() const { return this->numKeysPerRow; }
+    std::size_t getNumKeys() const { return this->numRows * this->numKeysPerRow; }
+    
+    void clear();
+    void setRowState(std::size_t row, int rowState);
+    int getRowState(std::size_t row) const;
+    bool getKeyState(std::size_t key) const;
+    
+    /**
+     * @brief Executes a XOR between two states.
+     * @return a state that represents the keys that changed of state.
+     */
+    KeyboardState operator^(const KeyboardState &other) const;
+    
+    /**
+     * @brief Executes an AND between two states.
+     */
+    KeyboardState operator&(const KeyboardState &mask) const;
+    
+    bool operator==(const KeyboardState &other) const;
+    bool operator!=(const KeyboardState &other) const { return !(*this == other); }
+    
+    /**
+     * @brief Checks if a keyboard state is full of 0.
+     */
+    bool empty() const;
+    
+    enum KeyPressType {
+        Idle, SingleKeyPress, MultiKeyPress
+    };
+    
+    /**
+     * @brief Determines the kind of key press present in the state.
+     * The keyboard state can represent an idle keyboard, a single key pressed
+     * or a key combination. This method determines which type of state this is.
+     * If a single key is represented, the key index can be retrieved.
+     * @param key   An integer where the single key pressed should be stored.
+     */
+    KeyPressType getKeyPressType(int *key = NULL) const;
+    KeyPressType getKeyPressType(int &key) const { return getKeyPressType(&key); }
+    
+    void streamTo(std::ostream &out) const;
+    
+private:
+    int getRowInfo(std::size_t row, std::size_t &wordIndex, std::size_t &rowShift, int &rowMask) const;
+
+    std::size_t numRows;
+    std::size_t numKeysPerRow;
+    int rowMask;
+    std::size_t numRowsPerWord;
+    std::size_t numKeysPerWord;
+    std::size_t numWords;
+    
+    typedef std::vector<int> Data;
+    Data data;
+};
+
+inline std::ostream & operator<<(std::ostream &out, const KeyboardState &s) {
+    s.streamTo(out);
+    return out;
+}
+
+} // kbd_mgr
+
+#endif // KEYBOARD_STATE_H_