Clickable.h

00001 /*
00002  *  Copyright 2014 Embedded Artists AB
00003  *
00004  *  Licensed under the Apache License, Version 2.0 (the "License");
00005  *  you may not use this file except in compliance with the License.
00006  *  You may obtain a copy of the License at
00007  *
00008  *    http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  *  Unless required by applicable law or agreed to in writing, software
00011  *  distributed under the License is distributed on an "AS IS" BASIS,
00012  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  *  See the License for the specific language governing permissions and
00014  *  limitations under the License.
00015  */
00016  
00017 #ifndef CLICKABLE_H
00018 #define CLICKABLE_H
00019 
00020 #include "lpc_swim.h"
00021 
00022 /**
00023  * Clickable is an abstract base class for the Button and ImageButton.
00024  */
00025 class Clickable {
00026 public:
00027 
00028     /** Creates a new clickable
00029      *
00030      *  This clickable will use a SWIM window to draw on. That window will use
00031      *  part of the full size frame buffer to draw on.
00032      *
00033      *  @param fb      the frame buffer
00034      *  @param x       the upper left corner of the button
00035      *  @param y       the upper left corner of the button
00036      *  @param width   the width of the button
00037      *  @param height  the height of the button
00038      */
00039   Clickable(COLOR_T* fb, uint16_t x, uint16_t y, uint16_t width, uint16_t height);
00040   virtual ~Clickable() {};
00041   
00042     /** Set the function to call when  clicked
00043      *
00044      *  Note that this function can be called with NULL as func to unregister the
00045      *  callback function.
00046      *
00047      *  @param func the function to call
00048      *  @param arc the argument to pass to the function when calling
00049      */
00050   void setAction(void (*func)(uint32_t arg), uint32_t arg) { _func = func; _funcArg = arg; }
00051   
00052     /** Process the touch event
00053      *
00054      *  This function will detect if and how the touch event affects it.
00055      *  If the event causes a click then the registered
00056      *  callback function is called before handle() returns.
00057      *
00058      *  The return value is to let the caller now if the button should be
00059      *  redrawn or not.
00060      *
00061      *  @param x       the touched x coordinate
00062      *  @param y       the touched y coordinate
00063      *  @param pressed true if the user pressed the display
00064      *
00065      *  @returns
00066      *       true if the button should be redrawn
00067      *       false if the event did not affect the button
00068      */
00069   bool handle(uint16_t x, uint16_t y, bool pressed);
00070 
00071     /** Test if the button is held down (usable for repeated presses)
00072      *
00073      *  @returns
00074      *       true if the button is pressed
00075      *       false otherwise
00076      */
00077   bool pressed() { return _pressed; }
00078   
00079   void bounds(int& x0, int& y0, int&x1, int&y1) {
00080       x0 = _win.xpmin;
00081       y0 = _win.ypmin;
00082       x1 = _win.xpmax;
00083       y1 = _win.ypmax;
00084   }
00085 
00086     /** Draws the button (on a new framebuffer if one is specified)
00087      *  @param fb      the frame buffer
00088      */
00089   virtual void draw(COLOR_T* fb = 0) = 0;
00090   
00091 protected:
00092   bool _enabled, _pressed;
00093   SWIM_WINDOW_T _win;
00094 
00095 private:
00096   void (*_func)(uint32_t arg);
00097   uint32_t _funcArg;
00098 };
00099 
00100 #endif /* CLICKABLE_H */