Resource.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 RESOURCE_H
00018 #define RESOURCE_H
00019 
00020 #include "mbed.h"
00021 #include "Image.h"
00022 
00023 /**
00024  * A resource container to pass around instead of using hardcoded data.
00025  *
00026  * Having a Resource class makes it possible to hide the source from the
00027  * user so that e.g. AppColorPicker doesn't need to know if the OK button
00028  * is loaded from an array or from a file system. The AppColorPicker only
00029  * need the resource. The Image class takes care of the loading.
00030  *
00031  * @code
00032  * #include "mbed.h"
00033  * #include "Resource.h"
00034  * #include "Image.h"
00035  *
00036  * const unsigned char ok_image1[] = { 137,80,78,71, ... };
00037  * int ok_image1_sz = sizeof(ok_image1);
00038  *
00039  * int main(void) {
00040  *    // initialize the display
00041  *    ...
00042  *
00043  *    // create the resources
00044  *    Resource resOk(ok_image1, ok_image1_sz, 40, 40);
00045  *    Resource resCancel("/qspi/cancel.png", 40, 40);
00046  *
00047  *    // add resource to application
00048  *    AppNetwork app ...;
00049  *    app.setResource(AppNetwork::Resource_Ok_Button, &resOk);
00050  *    app.setResource(AppNetwork::Resource_Cancel_Button, &resCancel);
00051  *
00052  *    // run application
00053  *    app.setup();
00054  *    app.runToCompletion();
00055  *
00056  *    ...
00057  * }
00058  * @endcode
00059  */
00060 class Resource {
00061 public:
00062 
00063     /** Create a new file resource.
00064      *
00065      *  The width and height are only guidelines and are often not used.
00066      *  The purpose is to allow e.g. the AppColorPicker to know the size
00067      *  of the image before it is loaded from the file system. It can also
00068      *  be used as a guide by the AppLauncher.
00069      *
00070      *  @param filename  the resource location
00071      *  @param width     the width of the image
00072      *  @param height    the height of the image
00073      */
00074     Resource(const char* filename, int width, int height);
00075 
00076     /** Create a new resource from a data array.
00077      *
00078      *  The width and height are only guidelines and are often not used.
00079      *  The purpose is to allow e.g. the AppColorPicker to know the size
00080      *  of the image before it is loaded from the file system. It can also
00081      *  be used as a guide by the AppLauncher.
00082      *
00083      *  @param data      the resource
00084      *  @param dataSize  number of bytes in data
00085      *  @param width     the width of the image
00086      *  @param height    the height of the image
00087      */
00088     Resource(const unsigned char* data, const unsigned int dataSize, int width, int height);
00089     ~Resource();
00090 
00091     /** Returns the width of the resource.
00092      *
00093      *  The width and height are only guidelines and are often not used.
00094      *  The purpose is to allow e.g. the AppColorPicker to know the size
00095      *  of the image before it is loaded from the file system. It can also
00096      *  be used as a guide by the AppLauncher.
00097      *
00098      *  @return the width
00099      */
00100     int width() { return _width; }
00101 
00102     /** Returns the height of the resource.
00103      *
00104      *  The width and height are only guidelines and are often not used.
00105      *  The purpose is to allow e.g. the AppColorPicker to know the size
00106      *  of the image before it is loaded from the file system. It can also
00107      *  be used as a guide by the AppLauncher.
00108      *
00109      *  @return the height
00110      */
00111     int height() { return _height; }
00112 
00113 private:
00114     friend class Image;
00115     
00116     int _width;
00117     int _height;
00118     bool _isFile;
00119     char* _filename;
00120     const unsigned char* _data;
00121     unsigned int _dataSize;
00122 
00123     Image::ImageData_t _img;
00124 };
00125 
00126 #endif