TextEditor.cpp

#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl_Input.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Return_Button.H>
#include <FL/Fl_Text_Editor.H> //莫名其妙报错
#include <FL/Fl_Menu_Item.H>
#include <FL/Fl_Menu_Bar.H>
#include <FL/fl_ask.H>
#include <FL/Fl_File_Chooser.H>

#include "TextEditor.h"
#include <stdio.h>
#include <cstdlib>

using namespace std;

class EditorWindow: public Fl_Double_Window {
    public:
        EditorWindow(int w, int h, const char *t);//构造函数，该函数接受三个参数，t参数是窗口的标题
        ~EditorWindow();

        //Fl_Double_Window和Fl_Text_Editor是FLTK库中的类，用于创建窗口和文本编辑器控件。
        //Fl_Input、Fl_Button和Fl_Return_Button也是FLTK库中的类，分别用于创建输入框、普通按钮和默认按钮。
        Fl_Window *replace_dlg; 
        Fl_Input *replace_find;
        Fl_Input *replace_with;
        Fl_Button *replace_all;
        //The Fl_Return_Button is a subclass of Fl_Button that generates a callback when it is pressed or when the user presses the Enter key.
        Fl_Return_Button *replace_next;
        Fl_Button *replace_cancel;

        Fl_Text_Editor *editor;
        char search[256];  
};

//some global variables
int changed = 0; //记录文件是否被修改过
char filename[256] = "";//记录当前打开的文件名
Fl_Text_Buffer *textbuf = 0;//记录当前打开的文件内容
char title[] = "Untitled";

static void build_Menu(Fl_Menu_Bar* menu, Fl_Window* window)
{
    /**Menubars and Menus**/
    Fl_Menu_Item menuitems[] = {
    /*FL_SUBMENU表示该菜单项是一个子菜单，快捷键，回调函数的ID，用于控制菜单项的行为*/
    {"&File",               0, 0, 0, FL_SUBMENU},
        {"&New File",       0, (Fl_Callback *)new_cb },
        {"&Open File...",   FL_CTRL + 'o', (Fl_Callback *)open_cb },
        //{"&Insert File...", FL_CTRL + 'i', (Fl_Callback *)insert_cb, 0, FL_MENU_DIVIDER }, //分割线
        {"&Save File",      FL_CTRL + 's', (Fl_Callback *)save_cb},
        {"Save File &As...",FL_CTRL + FL_SHIFT + 's', (Fl_Callback *)saveas_cb, 0, FL_MENU_DIVIDER},
        //{"New &View",       FL_ALT + 'v', (Fl_Callback *)view_cb, 0},//在FLTK库中，使用“&”符号可以将紧随其后的字母作为菜单项的快捷键。
        //{"&Close View",     FL_CTRL + 'w', (Fl_Callback *)close_cb, 0, FL_MENU_DIVIDER},
        {"E&xit",           FL_CTRL + 'q', (Fl_Callback *)quit_cb, 0},
        {0},//结束标志
    {"&Edit",               0, 0, 0, FL_SUBMENU},
        {"&Undo",           FL_CTRL + 'z', (Fl_Callback *)undo_cb, 0, FL_MENU_DIVIDER},
        {"Cu&t",            FL_CTRL + 'x', (Fl_Callback *)cut_cb },
        {"&Copy",           FL_CTRL + 'c', (Fl_Callback *)copy_cb },
        {"&Paste",          FL_CTRL + 'v', (Fl_Callback *)paste_cb },
        {"&Delete",         0, (Fl_Callback *)delete_cb},
        {0},
    {"&Search",             0, 0, 0, FL_SUBMENU},
        {"&Find...",        FL_CTRL + 'f', (Fl_Callback *)find_cb },
        {"F&ind Again",     FL_CTRL + 'g', find2_cb},
        {"&Replace...",     FL_CTRL + 'r', replace_cb },
        {"&Re&place Again", FL_CTRL + 't', replace2_cb },
        {0},
    {0}

};
    Fl_Menu_Bar *m = new Fl_Menu_Bar(0, 0, 640, 30);
    m->copy(menuitems);
}


// Fl_Window* new_View()
// {
//     EditorWindow* window = new EditorWindow(800, 600, title);
    
//     window->begin();
    
//     window->editor = new Fl_Text_Editor(10, 30, 780, 560);
//     window->editor->buffer(textbuf);
    
//     Fl_Menu_Bar* menuBar = new Fl_Menu_Bar(0, 0, 800, 30);
//     build_Menu(menuBar, window);

//     window->end();
//     window->resizable(window->editor);
//     window->editor->linenumber_width(60);

//     textbuf->add_modify_callback(changed_cb, window);
//     textbuf->call_modify_callbacks();
//     return window;
// }

/**Editing the Text**/
// EditorWindow* w = new EditorWindow(640, 480, title); 
// w->begin();
// w->editor = new Fl_Text_Editor(0, 30, 640, 370);
// w->editor->buffer(textbuf);
// // keep track of changes to the file, we also want to add a "modify" callback
// textbuf->add_modify_callback(changed_cb, w);
// textbuf->call_modify_callbacks();

/**The Replace Dialog**/
Fl_Window *replace_dlg = new Fl_Window(300, 105, "Replace");
Fl_Input *replace_find = new Fl_Input(70, 10, 200, 25, "Find:");
Fl_Input *replace_with = new Fl_Input(70, 40, 200, 25, "Replace:");
Fl_Button *replace_all = new Fl_Button(10, 70, 90, 25, "Replace All");
Fl_Button *replace_next = new Fl_Button(105, 70, 90, 25, "Replace Next");
Fl_Button *replace_cancel = new Fl_Button(230, 70, 60, 25, "Cancel");

/**Callbacks**/
void changed_cb(int, int nInserted, int nDeleted, int, const char*, void* v) {
    if((nInserted || nDeleted) && !loading) changed = 1;
    EditorWindow *w = (EditorWindow*)v;
    set_title(w);
    if(loading) w->editor->show_insert_position();
}

void copy_cb(Fl_Widget *, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    Fl_Text_Editor::kf_copy(0, e->editor);
    //0:int, which is the index of the selected text, 0 means the entire selected text will be copied to the clipboard
    //the third and fourth arguments are set to 0, which means that the entire selected text will be copied.
}

void cut_cb(Fl_Widget *, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    Fl_Text_Editor::kf_cut(0, e->editor);
    //0:int, which is the index of the selected text, 0 means the entire selected text will be copied to the clipboard
    //the third and fourth arguments are set to 0, which means that the entire selected text will be cut.
}

//删除选中文字
void delete_cb(Fl_Widget *, void* v) {
    textbuf->remove_selection();
}

//This callback function asks for a search string using the fl_input() convenience function and then calls the find2_cb() function to find the string
void find_cb(Fl_Widget* w, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    const char *val;

    val = fl_input("Search String:", e->search);
    if(val) {
        //user entered  a string, go find it!
        strcpy(e->search, val);
        find2_cb(w, v);
    }
}

//This function will find the next occurrence of the search string. If the search string is blank then we want to pop up the search dialog:
void find2_cb(Fl_Widget* w, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    if(e->search[0] == '\0') {
        //search string is blank; get a new one
        find_cb(w, v);
        return;
    }

    int pos = e->editor->insert_position();
    int found =  textbuf->search_forward(pos, e->search, &pos);
    if (found) {
        // Found a match; select and update the position...
        textbuf->select(pos, pos+strlen(e->search));
        e->editor->insert_position(pos+strlen(e->search));
        e->editor->show_insert_position();
    }
    else fl_alert("No occurrences of \'%s\' found!", e->search);
}

//new_cb() is called when the user presses the "New File" button. 
void new_cb(Fl_Widget*, void*) {
    if(!check_save()) return;

    filename[0] = '\0';
    textbuf->select(0, textbuf->length());
    textbuf->remove_selection();
    changed = 0;
    textbuf->call_modify_callbacks();
}

//open_cb() is called when the user presses the "Open File" button.
void open_cb(Fl_Widget*, void*) {
    if(!check_save()) return;
    //the title of the dialog box, the default file name or diretory(if any), A wildcard string that specifies the types of files
    char *newfile = fl_file_chooser("Open File?", "*", filename);//返回所选文件的地址
    if(newfile != NULL) load_file(newfile, -1);
}

void undo_cb(void)
{
    textbuf->undo();
}

//paste_cb() is called when the user presses the "Paste" button. 
void paste_cb(Fl_Widget*, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    Fl_Text_Editor::kf_paste(0, e->editor);
}

//quit_cb() is called when the user presses the "Exit" button. 
void quit_cb(Fl_Widget*, void*) {
    if(changed && !check_save())
        return;
    exit(0);
}

//replace_cb() is called when the user presses the "Replace" button. 
void replace_cb(Fl_Widget*, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    e->replace_dlg->show();
}

//replace2_cb() 
void replace2_cb(Fl_Widget*, void* v) {
    EditorWindow* e = (EditorWindow*)v;
    const char* find = e->replace_find->value();
    const char* replace = e->replace_with->value();

    if(find[0] == '\0') {
        //search string is blank; get a new one
        e->replace_dlg->show();
        return;
    }

    e->replace_dlg->hide();

    int pos = e->editor->insert_position();
    int found = textbuf->search_forward(pos, find, &pos);

    if(found) {
        //Found a match; update the position and replace text...
        textbuf->select(pos, pos+strlen(find));
        textbuf->remove_selection();
        textbuf->insert(pos, replace);
        textbuf->select(pos, pos+strlen(replace));
        e->editor->insert_position((pos+strlen(replace)));
        e->editor->show_insert_position();
    }
    else {
        fl_alert("No occurrences of \'%s\' found!", find);
    }

}

//replall_cb() is called when the user presses the "Replace All" button. 
void replacall_cb(Fl_Widget* , void* v) {
    EditorWindow* e = (EditorWindow*) v;
    const char* find = e->replace_find->value();
    const char* replace = e->replace_with->value();

    if(*find == '\0') {
        //Search string is blank; get a new one
        e->replace_dlg->show();
        return;
    }

    e->replace_dlg->hide();

    e->editor->insert_position(0);
    int times = 0;

    //loop through the whole string
    for(int found = 1; found;) {
        int pos = e->editor->insert_position();
        found = textbuf->search_forward(pos, find, &pos);

        if(found) {
            //Found a match; update the position and replace text...
            textbuf->select(pos, pos+strlen(find));
            textbuf->remove_selection();
            textbuf->insert(pos, replace);
            
            e->editor->insert_position(pos+strlen(replace));
            e->editor->show_insert_position();

            times++;
        }
    }

    if(times) fl_message("Replaced %d occurrences", times);
    else fl_alert("No occurrences of \'%s\' found!", find);


}

//replcan_cb(): hide the replace dialog
void replcan_cb(Fl_Widget*, void* v) {
    EditorWindow* e = (EditorWindow*) v;
    e->replace_dlg->hide();
}

//save_cb() is called when the user presses the "Save as" button.
void save_cb(void) {
    //No filename - get one
    if(filename[0] == '\0') {
        saveas_cb();
        return;
    }
    else save_file(filename);
    
} 

void saveas_cb(void) {
    char *newfile;
    /***
     * The title of the dialog box
     * A wildcard stringg
    */
    newfile = fl_file_chooser("Save File As?", "*", filename);  
    if(newfile!= NULL) save_file(newfile);
}


//Now we need other functions to make those call functions work
int check_save(void) {
    if(changed)  return 1;

    int r = fl_choice("Do you want to save your changes?", "Cancel", "Save", "Discard");

    if(r == 1) {
        save_cb();
        return !changed;
    }

    return (r == 2)? 1 : 0;
}

//load_file() loads the specific file into the textbuf class
void load_file(char *newfile, int ipos) {
    loading = 1; //this flag is set to 1 to prevent multiple file loads from occuring at the same time
    int insert = (ipos != -1);// insert falg is used to check if the file is being inserted into th editor
    //ipos is used to specify the position in the file where the file should be inserted. -1 indicates that the file is being inseted
    changed = insert;// if so, changed is set to 1
    if (!insert) strcpy(filename, " "); //if the file is not being inserted, the function set the filename empty
    
    int r;
    if(!insert) r = textbuf->insertfile(newfile, ipos);
    else r = textbuf->insertfile(newfile, ipos);

    if(r)
        fl_alert("Error reading from the file \'%s\':\n%s.", newfile, strerror(errno));
    else
        if(!insert) strcpy(filename, newfile);
    
    loading =0;
    textbuf->call_modify_callbacks();//used to notify any registered modification callbacks,
}

void save_file(char *newfile) {
    /**
    * 0 on success
    * non-zero on error (strerror() contains reason)
    * 1 indicates open for write failed (no data saved)
    * 2 indicates error occurred while writing data (data was partially saved)
    */
    if(textbuf->savefile(newfile))
        fl_alert("Error writing to the file \'%s\':\n%s.", newfile, strerror(errno));
    else
        strcpy(filename, newfile);
    changed = 0;
    textbuf->call_modify_callbacks();
}

void set_title(Fl_Window* w) {
    if(filename[0] == '\0') strcpy(title, "Untitled");
    else {
        char *slash;
        slash = strrchr(filename, '/');
#ifdef WIN32
    if(slash == NULL) slash = strrchr(filename, '\\');
#endif
    if (slash != NULL) strcpy(title, slash + 1);
    else strcpy(title, filename);
    }

    if(changed) strcat(title, " （modified）");

    w->label(title);
}

Fl_Window* new_view() {
    EditorWindow* window = new EditorWindow(800, 600, title);
    
    window->begin();
    
    window->editor = new Fl_Text_Editor(10, 30, 780, 560);
    window->editor->buffer(textbuf);
    
    Fl_Menu_Bar* menuBar = new Fl_Menu_Bar(0, 0, 800, 30);
    build_Menu(menuBar, window);

    window->end();
    window->resizable(window->editor);
    window->editor->linenumber_width(60);

    textbuf->add_modify_callback(changed_cb, window);
    textbuf->call_modify_callbacks();
    return window;
}


int main(int argc, char **argv) {
    textbuf = new Fl_Text_Buffer;
    Fl_Window* window = new_view();
    window->show(1, argv);
    if(argc > 1) load_file(argv[1], -1);
    return Fl::run();
}