fltk/src/Fl_Screen_Driver.cxx

//
// All screen related calls in a driver style class.
//
// 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:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

/**
 \cond DriverDev
 \addtogroup DriverDeveloper
 \{
 */

#include "Fl_Screen_Driver.H"
#include <FL/Fl_Image.H>
#include <FL/Fl.H>
#include <FL/Fl_Group.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Input.H>
#include "Fl_Window_Driver.H"
#include <FL/Fl_Image_Surface.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Tooltip.H>

char Fl_Screen_Driver::bg_set = 0;
char Fl_Screen_Driver::bg2_set = 0;
char Fl_Screen_Driver::fg_set = 0;

int Fl_Screen_Driver::keyboard_screen_scaling = 1;

Fl_Screen_Driver::Fl_Screen_Driver() :
num_screens(-1), text_editor_extra_key_bindings(NULL)
{
}

Fl_Screen_Driver::~Fl_Screen_Driver() {
}


void Fl_Screen_Driver::display(const char *) {
  // blank
}


int Fl_Screen_Driver::visual(int) {
  // blank
  return 1;
}


void Fl_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int mx, int my)
{
  screen_xywh(X, Y, W, H, screen_num(mx, my));
}


void Fl_Screen_Driver::screen_work_area(int &X, int &Y, int &W, int &H, int mx, int my)
{
  screen_work_area(X, Y, W, H, screen_num(mx, my));
}


int Fl_Screen_Driver::screen_count()
{
  if (num_screens < 0)
    init();
  return num_screens ? num_screens : 1;
}


void Fl_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int mx, int my, int mw, int mh)
{
  screen_xywh(X, Y, W, H, screen_num(mx, my, mw, mh));
}


int Fl_Screen_Driver::screen_num(int x, int y)
{
  int screen = 0;
  if (num_screens < 0) init();

  for (int i = 0; i < num_screens; i ++) {
    int sx, sy, sw, sh;
    screen_xywh(sx, sy, sw, sh, i);
    if ((x >= sx) && (x < (sx+sw)) && (y >= sy) && (y < (sy+sh))) {
      screen = i;
      break;
    }
  }
  return screen;
}


// Return the number of pixels common to the two rectangular areas
float Fl_Screen_Driver::fl_intersection(int x1, int y1, int w1, int h1,
                                    int x2, int y2, int w2, int h2)
{
  if(x1+w1 < x2 || x2+w2 < x1 || y1+h1 < y2 || y2+h2 < y1)
    return 0.;
  int int_left = x1 > x2 ? x1 : x2;
  int int_right = x1+w1 > x2+w2 ? x2+w2 : x1+w1;
  int int_top = y1 > y2 ? y1 : y2;
  int int_bottom = y1+h1 > y2+h2 ? y2+h2 : y1+h1;
  return (float)(int_right - int_left) * (int_bottom - int_top);
}


int Fl_Screen_Driver::screen_num(int x, int y, int w, int h)
{
  int best_screen = 0;
  float best_intersection = 0.;
  if (num_screens < 0) init();
  for (int i = 0; i < num_screens; i++) {
    int sx = 0, sy = 0, sw = 0, sh = 0;
    screen_xywh(sx, sy, sw, sh, i);
    float sintersection = fl_intersection(x, y, w, h, sx, sy, sw, sh);
    if (sintersection > best_intersection) {
      best_screen = i;
      best_intersection = sintersection;
    }
  }
  return best_screen;
}


const char *Fl_Screen_Driver::get_system_scheme()
{
  return fl_getenv("FLTK_SCHEME");
}

/** The bullet character used by default by Fl_Secret_Input */
int Fl_Screen_Driver::secret_input_character = 0x2022;

void Fl_Screen_Driver::compose_reset() {
  Fl::compose_state = 0;
}

void Fl_Screen_Driver::write_image_inside(Fl_RGB_Image *to, Fl_RGB_Image *from, int to_x, int to_y)
/* Copy the image "from" inside image "to" with its top-left angle at coordinates to_x, to_y.
Image depths can differ between "to" and "from".
*/
{
  int to_ld = (to->ld() == 0? to->w() * to->d() : to->ld());
  int from_ld = (from->ld() == 0? from->w() * from->d() : from->ld());
  uchar *tobytes = (uchar*)to->array + to_y * to_ld + to_x * to->d();
  const uchar *frombytes = from->array;
  int need_alpha = (from->d() == 3 && to->d() == 4);
  for (int i = 0; i < from->h(); i++) {
    if (from->d() == to->d()) memcpy(tobytes, frombytes, from->w() * from->d());
    else {
      for (int j = 0; j < from->w(); j++) {
        memcpy(tobytes + j * to->d(), frombytes + j * from->d(), from->d());
        if (need_alpha) *(tobytes + j * to->d() + 3) = 0xff;
      }
    }
    tobytes += to_ld;
    frombytes += from_ld;
  }
}


/* Captures rectangle x,y,w,h from a mapped window or GL window.
 All sub-GL-windows that intersect x,y,w,h, and their subwindows, are also captured.

 Arguments when this function is initially called:
 g: a window or GL window
 x,y,w,h: a rectangle in window g's coordinates
 full_img: NULL

 Arguments when this function recursively calls itself:
 g: an Fl_Group
 x,y,w,h: a rectangle in g's coordinates if g is a window, or in g's parent window coords if g is a group
 full_img: NULL, or a previously captured image that encompasses the x,y,w,h rectangle and that
 will be partially overwritten with the new capture

 Return value:
 An Fl_RGB_Image*, the depth of which is platform-dependent, containing the captured pixels,
 or NULL if capture failed.
 */
Fl_RGB_Image *Fl_Screen_Driver::traverse_to_gl_subwindows(Fl_Group *g, int x, int y, int w, int h,
                                                          Fl_RGB_Image *full_img)
{
  bool captured_subwin = false;
  if ( g->as_gl_window() ) {
    Fl_Device_Plugin *plugin = Fl_Device_Plugin::opengl_plugin();
    if (!plugin) return full_img;
    full_img = plugin->rectangle_capture(g, x, y, w, h);
  }
  else if ( g->as_window() ) {
    full_img = Fl::screen_driver()->read_win_rectangle(x, y, w, h, g->as_window(), true, &captured_subwin);
  }
  if (!full_img) return NULL;
  float full_img_scale =  (full_img && w > 0 ? float(full_img->data_w())/w : 1);
  int n = (captured_subwin ? 0 : g->children());
  for (int i = 0; i < n; i++) {
    Fl_Widget *c = g->child(i);
    if ( !c->visible() || !c->as_group()) continue;
    if ( c->as_window() ) {
      int origin_x = x; // compute intersection of x,y,w,h and the c window
      if (x < c->x()) origin_x = c->x();
      int origin_y = y;
      if (y < c->y()) origin_y = c->y();
      int maxi = x + w; if (maxi > c->x() + c->w()) maxi = c->x() + c->w();
      int width = maxi - origin_x;
      maxi = y + h; if (maxi > c->y() + c->h()) maxi = c->y() + c->h();
      int height = maxi - origin_y;
      if (width > 0 && height > 0) {
        Fl_RGB_Image *img = traverse_to_gl_subwindows(c->as_window(),  origin_x - c->x(),
                                                      origin_y - c->y(), width, height, full_img);
        if (img == full_img) continue;
        write_image_inside(full_img, img, (origin_x - x) * full_img_scale, (origin_y - y) * full_img_scale);
        delete img;
      }
    }
    else traverse_to_gl_subwindows(c->as_group(), x, y, w, h, full_img);
  }
  return full_img;
}


int Fl_Screen_Driver::input_widget_handle_key(int key, unsigned mods, unsigned shift, Fl_Input *input)
{
  switch (key) {
    case FL_Delete: {
      int selected = (input->position() != input->mark()) ? 1 : 0;
      if (mods==0 && shift && selected)
        return input->kf_copy_cut();            // Shift-Delete with selection (WP,NP,WOW,GE,KE,OF)
      if (mods==0 && shift && !selected)
        return input->kf_delete_char_right();   // Shift-Delete no selection (WP,NP,WOW,GE,KE,!OF)
      if (mods==0)          return input->kf_delete_char_right();       // Delete         (Standard)
      if (mods==FL_CTRL)    return input->kf_delete_word_right();       // Ctrl-Delete    (WP,!NP,WOW,GE,KE,!OF)
      return 0;                                                 // ignore other combos, pass to parent
    }

    case FL_Left:
      if (mods==0)          return input->kf_move_char_left();          // Left           (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_move_word_left();          // Ctrl-Left      (WP,NP,WOW,GE,KE,!OF)
      if (mods==FL_META)    return input->kf_move_char_left();          // Meta-Left      (WP,NP,?WOW,GE,KE)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_Right:
      if (mods==0)          return input->kf_move_char_right(); // Right          (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_move_word_right(); // Ctrl-Right     (WP,NP,WOW,GE,KE,!OF)
      if (mods==FL_META)    return input->kf_move_char_right(); // Meta-Right     (WP,NP,?WOW,GE,KE,!OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_Up:
      if (mods==0)          return input->kf_lines_up(1);               // Up             (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_move_up_and_sol(); // Ctrl-Up        (WP,!NP,WOW,GE,!KE,OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_Down:
      if (mods==0)          return input->kf_lines_down(1);             // Dn             (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_move_down_and_eol();       // Ctrl-Down      (WP,!NP,WOW,GE,!KE,OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_Page_Up:
      // Fl_Input has no scroll control, so instead we move the cursor by one page
      if (mods==0)          return input->kf_page_up();         // PageUp         (WP,NP,WOW,GE,KE)
      if (mods==FL_CTRL)    return input->kf_page_up();         // Ctrl-PageUp    (!WP,!NP,!WOW,!GE,KE,OF)
      if (mods==FL_ALT)     return input->kf_page_up();         // Alt-PageUp     (!WP,!NP,!WOW,!GE,KE,OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_Page_Down:
      if (mods==0)          return input->kf_page_down();               // PageDn         (WP,NP,WOW,GE,KE)
      if (mods==FL_CTRL)    return input->kf_page_down();               // Ctrl-PageDn    (!WP,!NP,!WOW,!GE,KE,OF)
      if (mods==FL_ALT)     return input->kf_page_down();               // Alt-PageDn     (!WP,!NP,!WOW,!GE,KE,OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_Home:
      if (mods==0)          return input->kf_move_sol();                // Home           (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_top();                     // Ctrl-Home      (WP,NP,WOW,GE,KE,OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_End:
      if (mods==0)          return input->kf_move_eol();                // End            (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_bottom();                  // Ctrl-End       (WP,NP,WOW,GE,KE,OF)
      return 0;                                                 // ignore other combos, pass to parent

    case FL_BackSpace:
      if (mods==0)          return input->kf_delete_char_left();        // Backspace      (WP,NP,WOW,GE,KE,OF)
      if (mods==FL_CTRL)    return input->kf_delete_word_left();        // Ctrl-Backspace (WP,!NP,WOW,GE,KE,!OF)
      return 0;
      // ignore other combos, pass to parent
  }
  return -1;
}


void Fl_Screen_Driver::rescale_all_windows_from_screen(int screen, float f)
{
  float old_f = this->scale(screen);
  //if (f == old_f) return;
  this->scale(screen, f);
  Fl_Graphics_Driver *d = Fl_Display_Device::display_device()->driver();
  d->scale(f);
  int i = 0, count = 0; // count top-level windows, except transient scale-displaying window
  Fl_Window *win = Fl::first_window();
  while (win) {
    if (!win->parent() &&
        (Fl_Window_Driver::driver(win)->screen_num() == screen || rescalable() == SYSTEMWIDE_APP_SCALING) &&
        win->user_data() != &Fl_Screen_Driver::transient_scale_display) {
      count++;
    }
    win = Fl::next_window(win);
  }
  if (count == 0)
    return;
  Fl_Window **win_array = new Fl_Window*[count];
  win = Fl::first_window(); // memorize all top-level windows
  while (win) {
    if (!win->parent() &&
        (Fl_Window_Driver::driver(win)->screen_num() == screen || rescalable() == SYSTEMWIDE_APP_SCALING) &&
        win->user_data() != &Fl_Screen_Driver::transient_scale_display) {
      win_array[i++] = win;
    }
    win = Fl::next_window(win);
  }
  for (i = count - 1; i >= 0; i--) { // rescale all top-level windows, finishing with front one
    win = win_array[i];
    Fl_Window_Driver::driver(win)->resize_after_scale_change(screen, old_f, f);
    win->wait_for_expose();
  }
  delete[] win_array;
}

struct WinAndTracker {
  Fl_Window *win;
  Fl_Widget_Tracker *tracker;
};

static void del_transient_window(WinAndTracker *data) {
  delete (Fl_Image*)data->win->shape();
  Fl::delete_widget(data->win);
  if (data->tracker) {
    if (data->tracker->exists()) {
      Fl::focus(data->tracker->widget());
      data->tracker->widget()->handle(FL_FOCUS);
    }
    delete data->tracker;
  }
  delete data;
}

void Fl_Screen_Driver::transient_scale_display(float f, int nscreen)
{
  if (!Fl::option(Fl::OPTION_SHOW_SCALING)) return;
  // transiently show the new scaling value using a shaped window
  int w = 150;
  // draw a white rounded box on black background
  Fl_Screen_Driver *d = Fl::screen_driver();
  float s = d->scale(nscreen);
  if (s > 3) s = 3; // limit the growth of the transient window
  Fl_Image_Surface *surf = new Fl_Image_Surface(w*s, w*s/2);
  Fl_Surface_Device::push_current(surf);
  fl_color(FL_BLACK);
  fl_rectf(-1, -1, w*s+2, w*s+2);
  Fl_Box *b = new Fl_Box(FL_RFLAT_BOX, 0, 0, w*s, w*s/2, "");
  b->color(FL_WHITE);
  surf->draw(b);
  delete b;
  Fl_RGB_Image* img = surf->image(); // img will be the window's shape
  Fl_Surface_Device::pop_current();
  delete surf;
  //create a window shaped with the rounded box
  int X, Y, W, H;
  Fl::screen_xywh(X, Y, W, H, nscreen);
  w /= d->scale(nscreen)/s;
  Fl_Window *win = new Fl_Window((X + W/2) -w/2, (Y + H/2) -w/4, w, w/2, 0);
  b = new Fl_Box(FL_FLAT_BOX, 0, 0, w, w/2, NULL);
  char str[10];
  sprintf(str, "%d %%", int(f * 100 + 0.5));
  b->copy_label(str);
  b->labelfont(FL_TIMES_BOLD);
  b->labelsize(30 * s / d->scale(nscreen));
  b->labelcolor(FL_BLACK);
  b->color(Fl_Tooltip::color());
  win->end();
  win->shape(img);
  win->user_data((void*)&transient_scale_display); // prevent this window from being rescaled later
  win->set_output();
  win->set_non_modal();
  Fl_Window_Driver::driver(win)->screen_num(nscreen);
  Fl_Window_Driver::driver(win)->force_position(1);
  WinAndTracker *data = new WinAndTracker;
  data->win = win;
  Fl_Widget *widget = Fl::focus();
  data->tracker = (widget ? new Fl_Widget_Tracker(widget) : NULL);
  win->show();
  Fl::add_timeout(1, (Fl_Timeout_Handler)del_transient_window, data); // delete after 1 sec
}

// respond to Ctrl-'+' and Ctrl-'-' and Ctrl-'0' (Ctrl-'=' is same as Ctrl-'+') by rescaling all windows
int Fl_Screen_Driver::scale_handler(int event)
{
  if (!keyboard_screen_scaling) return 0;
  if ( event != FL_SHORTCUT || (!Fl::event_command()) ) return 0;
  int key = Fl::event_key() & ~(FL_SHIFT+FL_COMMAND);
  if (key == '=' || key == '-' || key == '+' || key == '0' || key == 0xE0/* for '0' on Fr keyboard */) {
    int i, count;
    if (Fl::grab()) return 0; // don't rescale when menu windows are on
    Fl_Widget *wid = Fl::focus();
    if (!wid) return 0;
    int screen = Fl_Window_Driver::driver(wid->top_window())->screen_num();
    Fl_Screen_Driver *screen_dr = Fl::screen_driver();
    static float initial_scale = screen_dr->scale(screen);
#if defined(TEST_SCALING)
    // test scaling factors: lots of values from 0.3 to 8.0
    static float scaling_values[] = {
      0.30000, 0.33661, 0.37768, 0.42376, 0.47547,
      0.50000, 0.53348, 0.59858, 0.67162, 0.75357,
      0.84551, 0.94868, 1.00000, 1.06444, 1.19432,
      1.34005, 1.50000, 1.68702, 1.89287, 2.00000,
      2.12384, 7.0f/3,  2.38298, 8.0f/3,  3.00000,
      10.0f/3, 3.75000, 4.00000, 13.0f/3, 14.0f/3,
      5.00000, 16.0f/3, 17.0f/3, 6.00000, 7.00000,
      8.00000};
#else
    // scaling factors for the standard GUI
    static float scaling_values[] = {
      0.5, 2.f/3, 0.8, 0.9, 1.0,
      1.1, 1.2, 4.f/3, 1.5, 1.7,
      2.0, 2.4, 3.0};
#endif
    float f, old_f = screen_dr->scale(screen)/initial_scale;
    if (key == '0' || key == 0xE0) f = 1;
    else {
      count = sizeof(scaling_values)/sizeof(float);
      for (i = 0; i < count; i++) {
        if (old_f >= scaling_values[i] - 1e-4 && (i+1 >= count || old_f < scaling_values[i+1] - 1e-4)) {
          break;
        }
      }
      if (key == '-') i--; else i++;
      if (i < 0) i = 0;
      else if (i >= count) i = count - 1;
      f = scaling_values[i];
    }
    if (f == old_f) return 1;
    screen_dr->rescale_all_windows_from_screen(screen, f*initial_scale);
    Fl_Screen_Driver::transient_scale_display(f, screen);
    Fl::handle(FL_ZOOM_EVENT, NULL);
    return 1;
  }
  return 0;
}


// use the startup time scaling value
void Fl_Screen_Driver::use_startup_scale_factor()
{
  char *p;
  int s_count = screen_count();
  desktop_scale_factor();
  if ((p = fl_getenv("FLTK_SCALING_FACTOR"))) {
    float factor = 1;
    sscanf(p, "%f", &factor);
    for (int i = 0; i < s_count; i++)  scale(i, factor * scale(i));
  }
}


void Fl_Screen_Driver::open_display()
{
  open_display_platform();
  static bool been_here = false;
  if (!been_here) {
    been_here = true;
    if (rescalable()) {
      use_startup_scale_factor();
      if (keyboard_screen_scaling)
        Fl::add_handler(Fl_Screen_Driver::scale_handler);
      int mx, my;
      int ns = Fl::screen_driver()->get_mouse(mx, my);
      Fl_Graphics_Driver::default_driver().scale(scale(ns));
    }
  }
}


// simulation of XParseColor:
int Fl_Screen_Driver::parse_color(const char* p, uchar& r, uchar& g, uchar& b)
{
  if (*p == '#') p++;
  size_t n = strlen(p);
  size_t m = n/3;
  const char *pattern = 0;
  switch(m) {
    case 1: pattern = "%1x%1x%1x"; break;
    case 2: pattern = "%2x%2x%2x"; break;
    case 3: pattern = "%3x%3x%3x"; break;
    case 4: pattern = "%4x%4x%4x"; break;
    default: return 0;
  }
  int R,G,B; if (sscanf(p,pattern,&R,&G,&B) != 3) return 0;
  switch(m) {
    case 1: R *= 0x11; G *= 0x11; B *= 0x11; break;
    case 3: R >>= 4; G >>= 4; B >>= 4; break;
    case 4: R >>= 8; G >>= 8; B >>= 8; break;
  }
  r = (uchar)R; g = (uchar)G; b = (uchar)B;
  return 1;
}

void Fl_Screen_Driver::default_icons(const Fl_RGB_Image *icons[], int count) {}

/**
 \}
 \endcond
 */