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| -rw-r--r-- | examples/Makefile | 1 | ||||
| -rw-r--r-- | examples/texteditor-with-dynamic-colors.cxx | 138 |
2 files changed, 139 insertions, 0 deletions
diff --git a/examples/Makefile b/examples/Makefile index c97b75901..08c511590 100644 --- a/examples/Makefile +++ b/examples/Makefile @@ -31,6 +31,7 @@ ALL = clipboard$(EXEEXT) \ SVG_File_Surface$(EXEEXT) \ textdisplay-with-colors$(EXEEXT) \ texteditor-simple$(EXEEXT) \ + texteditor-with-dynamic-colors$(EXEEXT) \ tree-simple$(EXEEXT) \ tree-as-container$(EXEEXT) \ tree-custom-draw-items$(EXEEXT) \ diff --git a/examples/texteditor-with-dynamic-colors.cxx b/examples/texteditor-with-dynamic-colors.cxx new file mode 100644 index 000000000..458774a56 --- /dev/null +++ b/examples/texteditor-with-dynamic-colors.cxx @@ -0,0 +1,138 @@ +// +// "$Id$" +// +// How to use Fl_Text_Editor with dynamic colors. -erco 08/29/2018 +// Originally posted on fltk.general. +// +// Shows how to use the add_modify_callback() to dynamically apply colors +// to text while the user types. For demonstration purposes, we trivially +// color the digits 0-4 in green, 5-9 in red, and all else in black. +// +// The text buffer and style buffer are two parallel character arrays; +// chars in the *text* buffer are the text in the editor, and +// chars in the *style* buffer represent coloring + font information +// for the corresponding character in the text buffer. +// +// In this example, a style buffer table sets up these style buffer +// characters: 'A' to be black text, 'B' to be green, and 'C' for red. +// The style buffer uses the same font + font sizes, so the font sizes +// remain the same when colors are changed. +// +// Copyright 2018 Greg Ercolano. +// Copyright 1998-2018 by Bill Spitzak and others. +// +// This library is free software. Distribution and use rights are outlined in +// the file "COPYING" which should have been included with this file. If this +// file is missing or damaged, see the license at: +// +// http://www.fltk.org/COPYING.php +// +// Please report all bugs and problems on the following page: +// +// http://www.fltk.org/str.php +// +#include <FL/Fl.H> +#include <FL/Fl_Window.H> +#include <FL/Fl_Text_Editor.H> + +// Custom class to demonstrate a specialized text editor +class MyEditor : public Fl_Text_Editor { + + Fl_Text_Buffer *tbuff; // text buffer + Fl_Text_Buffer *sbuff; // style buffer + + // Modify callback handler + void ModifyCallback(int pos, // position of update + int nInserted, // number of inserted chars + int nDeleted, // number of deleted chars + int, // number of restyled chars (unused here) + const char*) { // text deleted (unused here) + + // Nothing inserted or deleted? + if (nInserted == 0 && nDeleted == 0) return; + + // Characters inserted into tbuff? + // Insert same number of chars into style buffer.. + // + if (nInserted > 0) { + char *style = new char[nInserted + 1]; // temp buffer + memset(style, 'A', nInserted); // init style to "A"s + style[nInserted] = '\0'; // terminate string + sbuff->insert(pos, style); // insert "A"s into style buffer + delete[] style; // done with temp buffer.. + } + + // Characters deleted from tbuff? + // Delete same number of chars from style buffer.. + // + if ( nDeleted > 0 ) { + sbuff->remove(pos, pos + nDeleted); + return; // nothing more to do; deleting won't affect our single char coloring + } + + // Focus on characters inserted + int start = pos; + int end = pos + nInserted; + //DEBUG fprintf(stderr, "add_modify_callback(): start/end=%d/%d, text='%.*s'\n", start, end, (end-start), tbuff->address(start)); + + // SIMPLE EXAMPLE: + // Color the digits 0-4 in green, 5-9 in red. + // + for ( int i=start; i<end; i++ ) { + unsigned int c = tbuff->char_at(i); + if ( strchr("01234", c) ) sbuff->replace(i, i+1, "B"); // style 'B' (green) + else if ( strchr("56789", c) ) sbuff->replace(i, i+1, "C"); // style 'C' (red) + else sbuff->replace(i, i+1, "A"); // style 'A' (black) + } + } + + static void ModifyCallback_STATIC(int pos, // position of update + int nInserted, // number of inserted chars + int nDeleted, // number of deleted chars + int nRestyled, // number of restyled chars + const char *deletedText, // text deleted + void *cbarg) { // callback data + MyEditor *med = (MyEditor*)cbarg; + med->ModifyCallback(pos, nInserted, nDeleted, nRestyled, deletedText); + } + +public: + MyEditor(int X,int Y,int W,int H) : Fl_Text_Editor(X,Y,W,H) { + // Style table for the respective styles + static const Fl_Text_Editor::Style_Table_Entry stable[] = { + // FONT COLOR FONT FACE FONT SIZE + // --------------- ----------- -------------- + { FL_BLACK, FL_COURIER, 14 }, // A - Black + { FL_DARK_GREEN, FL_COURIER, 14 }, // B - Green + { FL_RED, FL_COURIER, 14 }, // C - Red + }; + tbuff = new Fl_Text_Buffer(); // text buffer + sbuff = new Fl_Text_Buffer(); // style buffer + buffer(tbuff); + int stable_size = sizeof(stable)/sizeof(stable[0]); + highlight_data(sbuff, stable, stable_size, 'A', 0, 0); + tbuff->add_modify_callback(ModifyCallback_STATIC, (void*)this); + } + + void text(const char* val) { + tbuff->text(val); + } +}; + +int main() { + Fl_Window *win = new Fl_Window(720, 480, "Text Editor With Dynamic Coloring"); + MyEditor *med = new MyEditor(10,10,win->w()-20,win->h()-20); + // Initial text in editor. + med->text("In this editor, digits 0-4 are shown in green, 5-9 shown in red.\n" + "So here's some numbers 0123456789.\n" + "Coloring is handled automatically by the add_modify_callback().\n" + "\n" + "You can type here to test. "); + win->resizable(med); + win->show(); + return(Fl::run()); +} + +// +// End of "$Id$". +// |