Diff: mbed-src/api/Ticker.h

Revision:

5:3f93dd1d4cb3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-src/api/Ticker.h	Thu Sep 26 00:44:20 2013 -0500
@@ -0,0 +1,204 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_TICKER_H
+#define MBED_TICKER_H
+
+#include "TimerEvent.h"
+#include "FunctionPointer.h"
+#include "CallChain.h"
+
+namespace mbed {
+
+/** A Ticker is used to call a function at a recurring interval
+ *
+ *  You can use as many seperate Ticker objects as you require.
+ *
+ * Example:
+ * @code
+ * // Toggle the blinking led after 5 seconds
+ *
+ * #include "mbed.h"
+ *
+ * Ticker timer;
+ * DigitalOut led1(LED1);
+ * DigitalOut led2(LED2);
+ *
+ * int flip = 0;
+ *
+ * void attime() {
+ *     flip = !flip;
+ * }
+ *
+ * int main() {
+ *     timer.attach(&attime, 5);
+ *     while(1) {
+ *         if(flip == 0) {
+ *             led1 = !led1;
+ *         } else {
+ *             led2 = !led2;
+ *         }
+ *         wait(0.2);
+ *     }
+ * }
+ * @endcode
+ */
+class Ticker : public TimerEvent {
+
+public:
+
+    /** Attach a function to be called by the Ticker, specifiying the interval in seconds
+     *
+     *  @param fptr pointer to the function to be called
+     *  @param t the time between calls in seconds
+     *
+     *  @returns
+     *  The function object created for 'fptr'
+     */
+    pFunctionPointer_t attach(void (*fptr)(void), float t) {
+        return attach_us(fptr, t * 1000000.0f);
+    }
+
+    /** Add a function to be called by the Ticker at the end of the call chain
+     *
+     *  @param fptr the function to add
+     *
+     *  @returns
+     *  The function object created for 'fptr'
+     */
+    pFunctionPointer_t add_function(void (*fptr)(void)) {
+        return add_function_helper(fptr);
+    }
+
+    /** Add a function to be called by the Ticker at the beginning of the call chain
+     *
+     *  @param fptr the function to add
+     *
+     *  @returns
+     *  The function object created for 'fptr'
+     */
+    pFunctionPointer_t add_function_front(void (*fptr)(void)) {
+        return add_function_helper(fptr, true);
+    }
+
+    /** Attach a member function to be called by the Ticker, specifiying the interval in seconds
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     *  @param t the time between calls in seconds
+     *
+     *  @returns
+     *  The function object created for 'tptr' and 'mptr'
+     */
+    template<typename T>
+    pFunctionPointer_t attach(T* tptr, void (T::*mptr)(void), float t) {
+        return attach_us(tptr, mptr, t * 1000000.0f);
+    }
+
+    /** Add a function to be called by the Ticker at the end of the call chain
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     *
+     *  @returns
+     *  The function object created for 'tptr' and 'mptr'
+     */
+    template<typename T>
+    pFunctionPointer_t add_function(T* tptr, void (T::*mptr)(void)) {
+        return add_function_helper(tptr, mptr);
+    }
+
+    /** Add a function to be called by the Ticker at the beginning of the call chain
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     *
+     *  @returns
+     *  The function object created for 'tptr' and 'mptr'
+     */
+    template<typename T>
+    pFunctionPointer_t add_function_front(T* tptr, void (T::*mptr)(void)) {
+        return add_function_helper(tptr, mptr, true);
+    }
+
+    /** Attach a function to be called by the Ticker, specifiying the interval in micro-seconds
+     *
+     *  @param fptr pointer to the function to be called
+     *  @param t the time between calls in micro-seconds
+     *
+     *  @returns
+     *  The function object created for 'fptr'
+     */
+    pFunctionPointer_t attach_us(void (*fptr)(void), unsigned int t) {
+        _chain.clear();
+        pFunctionPointer_t pf = _chain.add(fptr);
+        setup(t);
+        return pf;
+    }
+
+    /** Attach a member function to be called by the Ticker, specifiying the interval in micro-seconds
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     *  @param t the time between calls in micro-seconds
+     *
+     *  @returns
+     *  The function object created for 'tptr' and 'mptr'
+     */
+    template<typename T>
+    pFunctionPointer_t attach_us(T* tptr, void (T::*mptr)(void), unsigned int t) {
+        _chain.clear();
+        pFunctionPointer_t pf = _chain.add(tptr, mptr);
+        setup(t);
+        return pf;
+    }
+
+    /** Detach the function
+     */
+    void detach();
+
+    /** Remove a function from the Ticker's call chain
+     *
+     *  @param pf the function object to remove
+     *
+     *  @returns
+     *  true if the function was found and removed, false otherwise
+     */
+    bool remove_function(pFunctionPointer_t pf) {
+        bool res = _chain.remove(pf);
+        if (res && _chain.size() == 0)
+            detach();
+        return res;
+    }
+
+protected:
+    void setup(unsigned int t);
+    pFunctionPointer_t add_function_helper(void (*fptr)(void), bool front=false);
+    virtual void handler();
+
+    template<typename T>
+    pFunctionPointer_t add_function_helper(T* tptr, void (T::*mptr)(void), bool front=false) {
+        if (_chain.size() == 0)
+            return NULL;
+        return front ? _chain.add_front(tptr, mptr) : _chain.add(tptr, mptr);
+    }
+
+    unsigned int _delay;
+    CallChain _chain;
+};
+
+} // namespace mbed
+
+#endif