PIKApp/libpikawidgets/pikapickbutton-win32.c

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2023-09-26 00:35:21 +02:00
/* LIBPIKA - The PIKA Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* pikapickbutton-win32.c
* Copyright (C) 2022 Luca Bacci <luca.bacci@outlook.com>
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gegl.h>
#include <gtk/gtk.h>
#include "libpikacolor/pikacolor.h"
#include "pikawidgetstypes.h"
#include "pikapickbutton.h"
#include "pikapickbutton-private.h"
#include "pikapickbutton-win32.h"
#include <sdkddkver.h>
#include <windows.h>
#include <windowsx.h>
#include <stdint.h>
/*
* NOTES:
*
* This implementation is based on gtk/gtkcolorpickerwin32.c from GTK.
*
* We install a low-level mouse hook so that color picking continues
* even when switching active windows.
*
* Beyond that, we also create keep-above, input-only HWNDs and place
* them on the screen to cover each monitor. This is done to show our
* custom cursor and to avoid giving input to other windows: that way
* the desktop appears "frozen" while picking the color.
*
* Finally, we also set up a low-level keyboard hook to dismiss color-
* picking mode whenever the user presses <ESC>.
*
* Note that low-level hooks for mouse and keyboard do not use any DLL
* injection and are thus non-invasive.
*
* For GTK4: consider using an appropriate GDK surface for input-only
* windows. This'd enable us to also get Wintab input when CXO_SYSTEM
* is not set.
*/
typedef struct
{
HMONITOR handle;
wchar_t *device;
HDC hdc;
POINT screen_origin;
int logical_width;
int logical_height;
int physical_width;
int physical_height;
} MonitorData;
GList *pickers;
HHOOK mouse_hook;
HHOOK keyboard_hook;
ATOM notif_window_class;
HWND notif_window_handle;
GArray *monitors;
ATOM input_window_class;
GArray *input_window_handles;
/* Utils */
static HMODULE this_module (void);
static MonitorData * monitors_find_for_logical_point (POINT logical);
static MonitorData * monitors_find_for_physical_point (POINT physical);
static POINT logical_to_physical (MonitorData *data,
POINT logical);
static void destroy_window (gpointer ptr);
/* Mouse cursor */
static HCURSOR create_cursor_from_rgba32_pixbuf (GdkPixbuf *pixbuf,
POINT hotspot);
static HCURSOR create_cursor (void);
/* Low-level mouse hook */
static LRESULT CALLBACK mouse_procedure (int nCode,
WPARAM wParam,
LPARAM lParam);
static gboolean ensure_mouse_hook (void);
static void remove_mouse_hook (void);
/* Low-level keyboard hook */
static LRESULT CALLBACK keyboard_procedure (int nCode,
WPARAM wParam,
LPARAM lParam);
static gboolean ensure_keyboard_hook (void);
static void remove_keyboard_hook (void);
/* Input-only window */
static LRESULT CALLBACK input_window_procedure (HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam);
static gboolean ensure_input_window_class (void);
static void remove_input_window_class (void);
static HWND create_input_window (POINT origin,
int width,
int height);
/* Hidden notification window */
static LRESULT CALLBACK notif_window_procedure (HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam);
static gboolean ensure_notif_window_class (void);
static void remove_notif_window_class (void);
static gboolean ensure_notif_window (void);
static void remove_notif_window (void);
/* Monitor enumeration and discovery */
static void monitor_data_free (gpointer ptr);
static BOOL CALLBACK enum_monitor_callback (HMONITOR hMonitor,
HDC hDC,
RECT *pRect,
LPARAM lParam);
static GArray* enumerate_monitors (void);
/* PikaPickButtonWin32 */
static void ensure_input_windows (void);
static void remove_input_windows (void);
static void ensure_monitors (void);
static void remove_monitors (void);
static void ensure_screen_data (void);
static void remove_screen_data (void);
static void screen_changed (void);
static void ensure_screen_tracking (void);
static void remove_screen_tracking (void);
static PikaRGB pick_color_with_gdi (POINT physical_point);
static void user_picked (MonitorData *monitor,
POINT physical_point);
void _pika_pick_button_win32_pick (PikaPickButton *button);
static void stop_picking (void);
/* {{{ Utils */
/* Gets a handle to the module containing this code.
* Works regardless if we're building a shared or
* static library */
static HMODULE
this_module (void)
{
extern IMAGE_DOS_HEADER __ImageBase;
return (HMODULE) &__ImageBase;
}
static MonitorData*
monitors_find_for_logical_point (POINT logical)
{
HMONITOR monitor_handle;
guint i;
monitor_handle = MonitorFromPoint (logical, MONITOR_DEFAULTTONULL);
if (!monitor_handle)
return NULL;
ensure_monitors ();
for (i = 0; i < monitors->len; i++)
{
MonitorData *data = &g_array_index (monitors, MonitorData, i);
if (data->handle == monitor_handle)
return data;
}
return NULL;
}
static MonitorData*
monitors_find_for_physical_point (POINT physical)
{
guint i;
ensure_monitors ();
for (i = 0; i < monitors->len; i++)
{
MonitorData *data = &g_array_index (monitors, MonitorData, i);
RECT physical_rect;
physical_rect.left = data->screen_origin.x;
physical_rect.top = data->screen_origin.y;
physical_rect.right = physical_rect.left + data->physical_width;
physical_rect.bottom = physical_rect.top + data->physical_height;
/* TODO: tolerance */
if (PtInRect (&physical_rect, physical))
return data;
}
return NULL;
}
static POINT
logical_to_physical (MonitorData *data,
POINT logical)
{
POINT physical = logical;
if (data &&
(data->logical_width != data->physical_width) &&
data->logical_width > 0 && data->physical_width > 0)
{
double dpi_scale = (double) data->physical_width /
(double) data->logical_width;
physical.x = logical.x * dpi_scale;
physical.y = logical.y * dpi_scale;
}
return physical;
}
static void
destroy_window (gpointer ptr)
{
HWND *hwnd = (HWND*) ptr;
DestroyWindow (*hwnd);
}
/* }}}
* {{{ Mouse cursor */
static HCURSOR
create_cursor_from_rgba32_pixbuf (GdkPixbuf *pixbuf,
POINT hotspot)
{
struct {
BITMAPV5HEADER header;
RGBQUAD colors[2];
} info;
HBITMAP bitmap = NULL;
uint8_t *bitmap_data = NULL;
HBITMAP mask = NULL;
uint8_t *mask_data = NULL;
unsigned int mask_stride;
HDC hdc = NULL;
int width;
int height;
int size;
int stride;
const uint8_t *pixbuf_data = NULL;
int i_offset;
int j_offset;
int i;
int j;
ICONINFO icon_info;
HICON icon = NULL;
if (gdk_pixbuf_get_n_channels (pixbuf) != 4)
goto cleanup;
hdc = GetDC (NULL);
if (!hdc)
goto cleanup;
width = gdk_pixbuf_get_width (pixbuf);
height = gdk_pixbuf_get_height (pixbuf);
stride = gdk_pixbuf_get_rowstride (pixbuf);
size = MAX (width, height);
pixbuf_data = gdk_pixbuf_read_pixels (pixbuf);
memset (&info, 0, sizeof (info));
info.header.bV5Size = sizeof (info.header);
info.header.bV5Width = size;
info.header.bV5Height = size;
/* Since Windows XP the OS supports mouse cursors as 32bpp
* bitmaps with alpha channel that are laid out as BGRA32
* (assuming little-endian) */
info.header.bV5Planes = 1;
info.header.bV5BitCount = 32;
info.header.bV5Compression = BI_BITFIELDS;
info.header.bV5BlueMask = 0x000000FF;
info.header.bV5GreenMask = 0x0000FF00;
info.header.bV5RedMask = 0x00FF0000;
info.header.bV5AlphaMask = 0xFF000000;
bitmap = CreateDIBSection (hdc, (BITMAPINFO*) &info, DIB_RGB_COLORS,
(void**) &bitmap_data, NULL, 0);
if (!bitmap || !bitmap_data)
{
g_warning ("CreateDIBSection failed with error code %u",
(unsigned) GetLastError ());
goto cleanup;
}
/* We also need to provide a proper mask HBITMAP, otherwise
* CreateIconIndirect() fails with ERROR_INVALID_PARAMETER.
* This mask bitmap is a bitfield indicating whether the */
memset (&info, 0, sizeof (info));
info.header.bV5Size = sizeof (info.header);
info.header.bV5Width = size;
info.header.bV5Height = size;
info.header.bV5Planes = 1;
info.header.bV5BitCount = 1;
info.header.bV5Compression = BI_RGB;
info.colors[0] = (RGBQUAD){0x00, 0x00, 0x00};
info.colors[1] = (RGBQUAD){0xFF, 0xFF, 0xFF};
mask = CreateDIBSection (hdc, (BITMAPINFO*) &info, DIB_RGB_COLORS,
(void**) &mask_data, NULL, 0);
if (!mask || !mask_data)
{
g_warning ("CreateDIBSection failed with error code %u",
(unsigned) GetLastError ());
goto cleanup;
}
/* MSDN says mask rows are aligned to LONG boundaries */
mask_stride = (((size + 31) & ~31) >> 3);
if (width > height)
{
i_offset = 0;
j_offset = (width - height) / 2;
}
else
{
i_offset = (height - width) / 2;
j_offset = 0;
}
for (j = 0; j < height; j++) /* loop over all the bitmap rows */
{
uint8_t *bitmap_row = bitmap_data + 4 * ((j + j_offset) * size + i_offset);
uint8_t *mask_byte = mask_data + (j + j_offset) * mask_stride + i_offset / 8;
unsigned int mask_bit = (0x80 >> (i_offset % 8));
const uint8_t *pixbuf_row = pixbuf_data + (height - j - 1) * stride;
for (i = 0; i < width; i++) /* loop over the current bitmap row */
{
uint8_t *bitmap_pixel = bitmap_row + 4 * i;
const uint8_t *pixbuf_pixel = pixbuf_row + 4 * i;
/* Assign to destination pixel from source pixel
* by also swapping channels as appropriate */
bitmap_pixel[0] = pixbuf_pixel[2];
bitmap_pixel[1] = pixbuf_pixel[1];
bitmap_pixel[2] = pixbuf_pixel[0];
bitmap_pixel[3] = pixbuf_pixel[3];
if (pixbuf_pixel[3] == 0)
mask_byte[0] |= mask_bit; /* turn ON bit */
else
mask_byte[0] &= ~mask_bit; /* turn OFF bit */
mask_bit >>= 1;
if (mask_bit == 0)
{
mask_bit = 0x80;
mask_byte++;
}
}
}
memset (&icon_info, 0, sizeof (icon_info));
icon_info.fIcon = FALSE;
icon_info.xHotspot = hotspot.x;
icon_info.yHotspot = hotspot.y;
icon_info.hbmMask = mask;
icon_info.hbmColor = bitmap;
icon = CreateIconIndirect (&icon_info);
if (!icon)
{
g_warning ("CreateIconIndirect failed with error code %u",
(unsigned) GetLastError ());
goto cleanup;
}
cleanup:
if (mask)
DeleteObject (mask);
if (bitmap)
DeleteObject (bitmap);
if (hdc)
ReleaseDC (NULL, hdc);
return (HCURSOR) icon;
}
static HCURSOR
create_cursor (void)
{
GdkPixbuf *pixbuf = NULL;
GError *error = NULL;
HCURSOR cursor = NULL;
pixbuf = gdk_pixbuf_new_from_resource ("/technology.heckin/color-picker-cursors/cursor-color-picker.png",
&error);
if (!pixbuf)
{
g_critical ("gdk_pixbuf_new_from_resource failed: %s",
error ? error->message : "unknown error");
goto cleanup;
}
g_clear_error (&error);
cursor = create_cursor_from_rgba32_pixbuf (pixbuf, (POINT){ 1, 30 });
cleanup:
g_clear_error (&error);
g_clear_object (&pixbuf);
return cursor;
}
/* }}}
* {{{ Low-level mouse hook */
/* This mouse procedure can detect clicks made on any
* application window. Countrary to mouse capture, this
* method continues to work even after switching active
* windows. */
static LRESULT CALLBACK
mouse_procedure (int nCode,
WPARAM wParam,
LPARAM lParam)
{
if (nCode == HC_ACTION)
{
MSLLHOOKSTRUCT *info = (MSLLHOOKSTRUCT*) lParam;
switch (wParam)
{
case WM_LBUTTONDOWN:
case WM_MBUTTONDOWN:
case WM_RBUTTONDOWN:
case WM_XBUTTONDOWN:
{
POINT physical;
MonitorData *data;
if (pickers == NULL)
break;
/* A low-level mouse hook always receives points in
* per-monitor DPI-aware screen coordinates, regardless of
* the DPI awareness setting of the application. */
physical = info->pt;
data = monitors_find_for_physical_point (physical);
if (!data)
g_message ("Captured point (%ld, %ld) doesn't belong to any monitor",
(long) physical.x, (long) physical.y);
user_picked (data, physical);
/* It's safe to remove a hook from within its callback.
* Anyway this can even be called from an idle callback,
* as the hook does nothing if there are no pickers.
* (In that case also the ensure functions have to be
* scheduled in an idle callback) */
stop_picking ();
return (wParam == WM_XBUTTONDOWN) ? TRUE : 0;
}
break;
default:
break;
}
}
return CallNextHookEx (NULL, nCode, wParam, lParam);
}
static gboolean
ensure_mouse_hook (void)
{
if (!mouse_hook)
{
mouse_hook = SetWindowsHookExW (WH_MOUSE_LL, mouse_procedure, this_module (), 0);
if (!mouse_hook)
{
g_warning ("SetWindowsHookEx failed with error code %u",
(unsigned) GetLastError ());
return FALSE;
}
}
return TRUE;
}
static void
remove_mouse_hook (void)
{
if (mouse_hook)
{
if (!UnhookWindowsHookEx (mouse_hook))
{
g_warning ("UnhookWindowsHookEx failed with error code %u",
(unsigned) GetLastError ());
return;
}
mouse_hook = NULL;
}
}
/* }}}
* {{{ Low-level keyboard hook */
/* This is used to stop picking anytime the user presses ESC */
static LRESULT CALLBACK
keyboard_procedure (int nCode,
WPARAM wParam,
LPARAM lParam)
{
if (nCode == HC_ACTION)
{
KBDLLHOOKSTRUCT *info = (KBDLLHOOKSTRUCT*) lParam;
switch (wParam)
{
case WM_KEYDOWN:
case WM_SYSKEYDOWN:
if (info->vkCode == VK_ESCAPE)
{
stop_picking ();
return 1;
}
break;
default:
break;
}
}
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
static gboolean
ensure_keyboard_hook (void)
{
if (!keyboard_hook)
{
keyboard_hook = SetWindowsHookExW (WH_KEYBOARD_LL, keyboard_procedure, this_module (), 0);
if (!keyboard_hook)
{
g_warning ("SetWindowsHookEx failed with error code %u",
(unsigned) GetLastError ());
return FALSE;
}
}
return TRUE;
}
static void
remove_keyboard_hook (void)
{
if (keyboard_hook)
{
if (!UnhookWindowsHookEx (keyboard_hook))
{
g_warning ("UnhookWindowsHookEx failed with error code %u",
(unsigned) GetLastError ());
return;
}
keyboard_hook = NULL;
}
}
/* }}}
* {{{ Input-only windows */
/* Those input-only windows are placed to cover each monitor on
* the screen and serve two purposes: display our custom mouse
* cursor and freeze the desktop by avoiding interaction of the
* mouse with other applications */
static LRESULT CALLBACK
input_window_procedure (HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam)
{
switch (uMsg)
{
case WM_NCCREATE:
/* The shell automatically hides the taskbar when a window
* covers the entire area of a monitor (fullscreened). In
* order to avoid that, we can set a special property on
* the window
* See the docs for ITaskbarList2::MarkFullscreenWindow()
* on MSDN for more informations */
if (!SetPropW (hwnd, L"NonRudeHWND", (HANDLE) TRUE))
g_warning_once ("SetPropW failed with error code %u",
(unsigned) GetLastError ());
break;
case WM_NCDESTROY:
/* We have to remove window properties manually before the
* window gets destroyed */
if (!RemovePropW (hwnd, L"NonRudeHWND"))
g_warning_once ("SetPropW failed with error code %u",
(unsigned) GetLastError ());
break;
/* Avoid any drawing at all. Here we block processing of the
* default window procedure, although we set the NULL_BRUSH
* as the window class's background brush, so even the default
* window procedure wouldn't draw anything at all */
case WM_ERASEBKGND:
return 1;
case WM_PAINT:
{
#if 1
PAINTSTRUCT ps;
BeginPaint(hwnd, &ps);
EndPaint(hwnd, &ps);
#else
UINT flags = RDW_VALIDATE |
RDW_NOFRAME |
RDW_NOERASE;
RedrawWindow (hwnd, NULL, NULL, flags);
#endif
}
return 0;
#if 0
case WM_SYNCPAINT:
return 0;
#endif
case WM_MOUSEACTIVATE:
/* This can be useful in case we want to avoid
* using a mouse hook */
return MA_NOACTIVATE;
/* Anytime we detect a mouse click, pick the color. Note that
* this is rarely used as the mouse hook would process the
* clicks before that */
case WM_LBUTTONDOWN:
case WM_MBUTTONDOWN:
case WM_RBUTTONDOWN:
case WM_XBUTTONDOWN:
{
POINT logical = (POINT){GET_X_LPARAM (lParam), GET_Y_LPARAM (lParam)};
MonitorData *data = monitors_find_for_logical_point (logical);
POINT physical = logical_to_physical (data, logical);
if (!data)
g_message ("Captured point (%ld, %ld) doesn't belong to any monitor",
(long) logical.x, (long) logical.y);
user_picked (data, physical);
stop_picking ();
}
return (uMsg == WM_XBUTTONDOWN) ? TRUE : 0;
default:
break;
}
return DefWindowProcW (hwnd, uMsg, wParam, lParam);
}
static gboolean
ensure_input_window_class (void)
{
if (!input_window_class)
{
WNDCLASSEXW wndclassex;
HCURSOR cursor = create_cursor ();
memset (&wndclassex, 0, sizeof (wndclassex));
wndclassex.cbSize = sizeof (wndclassex);
wndclassex.hInstance = this_module ();
wndclassex.lpszClassName = L"PikaPickButtonInputWindowClass";
wndclassex.lpfnWndProc = input_window_procedure;
wndclassex.hbrBackground = GetStockObject (NULL_BRUSH);
wndclassex.hCursor = cursor ?
cursor :
LoadImageW (NULL,
(LPCWSTR)(guintptr)IDC_CROSS,
IMAGE_CURSOR, 0, 0,
LR_DEFAULTSIZE | LR_SHARED);
input_window_class = RegisterClassExW (&wndclassex);
if (input_window_class == 0)
{
g_warning ("RegisterClassExW failed with error code %u",
(unsigned) GetLastError ());
if (cursor)
DestroyCursor (cursor);
return FALSE;
}
}
return TRUE;
}
static void
remove_input_window_class (void)
{
if (input_window_class)
{
LPCWSTR name = (LPCWSTR)(guintptr)input_window_class;
UnregisterClassW (name, this_module ());
input_window_class = 0;
}
}
/* create_input_window expects logical screen coordinates */
static HWND
create_input_window (POINT origin,
int width,
int height)
{
DWORD stylex = WS_EX_NOACTIVATE | WS_EX_TOPMOST;
LPCWSTR wclass;
LPCWSTR title = L"Pika Input Window";
DWORD style = WS_POPUP;
HWND hwnd;
if (!ensure_input_window_class ())
return FALSE;
/* This must go after the ensure_input_window_class */
wclass = (LPCWSTR)(guintptr)input_window_class;
hwnd = CreateWindowExW (stylex, wclass, title, style,
origin.x, origin.y, width, height,
NULL, NULL, this_module (), NULL);
if (hwnd == NULL)
{
g_warning_once ("CreateWindowExW failed with error code %u",
(unsigned) GetLastError ());
return FALSE;
}
ShowWindow (hwnd, SW_SHOWNOACTIVATE);
return hwnd;
}
/* }}}
* {{{ Hidden notification window */
/* We setup a hidden window to listen for WM_DISPLAYCAHNGE
* messages and reposition the input-only windows on the
* screen */
static LRESULT CALLBACK
notif_window_procedure (HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam)
{
switch (uMsg)
{
case WM_DISPLAYCHANGE:
screen_changed ();
break;
default:
break;
}
return DefWindowProcW (hwnd, uMsg, wParam, lParam);
}
static gboolean
ensure_notif_window_class (void)
{
if (!notif_window_class)
{
WNDCLASSEXW wndclassex;
memset (&wndclassex, 0, sizeof (wndclassex));
wndclassex.cbSize = sizeof (wndclassex);
wndclassex.hInstance = this_module ();
wndclassex.lpszClassName = L"PikaPickButtonNotifWindowClass";
wndclassex.lpfnWndProc = notif_window_procedure;
notif_window_class = RegisterClassExW (&wndclassex);
if (notif_window_class == 0)
{
g_warning ("RegisterClassExW failed with error code %u",
(unsigned) GetLastError ());
return FALSE;
}
}
return TRUE;
}
static void
remove_notif_window_class (void)
{
if (notif_window_class)
{
LPCWSTR name = (LPCWSTR)(guintptr)notif_window_class;
UnregisterClassW (name, this_module ());
notif_window_class = 0;
}
}
static gboolean
ensure_notif_window (void)
{
if (!ensure_notif_window_class ())
return FALSE;
if (!notif_window_handle)
{
DWORD stylex = 0;
LPCWSTR wclass = (LPCWSTR)(guintptr)notif_window_class;
LPCWSTR title = L"Pika Notifications Window";
DWORD style = WS_POPUP;
notif_window_handle = CreateWindowExW (stylex, wclass,
title, style,
0, 0, 1, 1,
NULL, NULL,
this_module (),
NULL);
if (notif_window_handle == NULL)
{
g_warning_once ("CreateWindowExW failed with error code %u",
(unsigned) GetLastError ());
return FALSE;
}
}
return TRUE;
}
static void
remove_notif_window (void)
{
if (notif_window_handle)
{
DestroyWindow (notif_window_handle);
notif_window_handle = NULL;
}
remove_notif_window_class ();
}
/* }}}
* {{{ Monitor enumeration and discovery */
static void
monitor_data_free (gpointer ptr)
{
MonitorData *data = (MonitorData*) ptr;
if (data->device)
free (data->device);
}
static BOOL CALLBACK
enum_monitor_callback (HMONITOR hMonitor,
HDC hDC,
RECT *pRect,
LPARAM lParam)
{
GArray *result = (GArray*) lParam;
MonitorData data;
MONITORINFOEXW info;
DEVMODEW devmode;
const BOOL CALLBACK_CONTINUE = TRUE;
const BOOL CALLBACK_STOP = FALSE;
if (!pRect)
return CALLBACK_CONTINUE;
if (IsRectEmpty (pRect))
return CALLBACK_CONTINUE;
memset (&data, 0, sizeof (data));
data.handle = hMonitor;
data.hdc = hDC;
data.screen_origin.x = pRect->left;
data.screen_origin.y = pRect->top;
data.logical_width = pRect->right - pRect->left;
data.logical_height = pRect->bottom - pRect->top;
memset (&info, 0, sizeof (info));
info.cbSize = sizeof (info);
if (!GetMonitorInfoW (hMonitor, (MONITORINFO*) &info))
{
g_warning_once ("GetMonitorInfo failed with error code %u",
(unsigned) GetLastError ());
return CALLBACK_CONTINUE;
}
data.device = _wcsdup (info.szDevice);
memset (&devmode, 0, sizeof (devmode));
devmode.dmSize = sizeof (devmode);
if (!EnumDisplaySettingsExW (info.szDevice,
ENUM_CURRENT_SETTINGS,
&devmode, EDS_ROTATEDMODE))
{
g_warning_once ("EnumDisplaySettingsEx failed with error code %u",
(unsigned) GetLastError ());
return CALLBACK_CONTINUE;
}
if (devmode.dmPelsWidth)
data.physical_width = devmode.dmPelsWidth;
if (devmode.dmPelsHeight)
data.physical_height = devmode.dmPelsHeight;
g_array_append_val (result, data);
if (result->len >= 100)
return CALLBACK_STOP;
return CALLBACK_CONTINUE;
}
static GArray*
enumerate_monitors (void)
{
int count_monitors;
guint length_hint;
GArray *result;
count_monitors = GetSystemMetrics (SM_CMONITORS);
if (count_monitors > 0 && count_monitors < 100)
length_hint = (guint) count_monitors;
else
length_hint = 1;
result = g_array_sized_new (FALSE, TRUE, sizeof (MonitorData), length_hint);
g_array_set_clear_func (result, monitor_data_free);
if (!EnumDisplayMonitors (NULL, NULL, enum_monitor_callback, (LPARAM) result))
{
g_warning ("EnumDisplayMonitors failed with error code %u",
(unsigned) GetLastError ());
}
return result;
}
static void
ensure_input_windows (void)
{
ensure_monitors ();
if (!input_window_handles)
{
guint i;
input_window_handles = g_array_sized_new (FALSE, TRUE,
sizeof (HWND),
monitors->len);
g_array_set_clear_func (input_window_handles, destroy_window);
for (i = 0; i < monitors->len; i++)
{
MonitorData *data = &g_array_index (monitors, MonitorData, i);
HWND hwnd = create_input_window (data->screen_origin,
data->logical_width,
data->logical_height);
if (hwnd)
g_array_append_val (input_window_handles, hwnd);
}
}
}
static void
remove_input_windows (void)
{
if (input_window_handles)
{
g_array_free (input_window_handles, TRUE);
input_window_handles = NULL;
}
}
static void
ensure_monitors (void)
{
if (!monitors)
monitors = enumerate_monitors ();
}
static void
remove_monitors (void)
{
if (monitors)
{
g_array_free (monitors, TRUE);
monitors = NULL;
}
}
static void
ensure_screen_data (void)
{
ensure_monitors ();
ensure_input_windows ();
}
static void
remove_screen_data (void)
{
remove_input_windows ();
remove_monitors ();
}
static void
screen_changed (void)
{
remove_screen_data ();
ensure_screen_data ();
}
static void
ensure_screen_tracking (void)
{
ensure_notif_window ();
screen_changed ();
}
static void
remove_screen_tracking (void)
{
remove_notif_window ();
remove_screen_data ();
}
/* }}}
* {{{ PikaPickButtonWin32 */
/* pick_color_with_gdi is based on the GDI GetPixel() function.
* Note that GDI only returns 8bit per-channel color data, but
* as of today there's no documented method to retrieve colors
* at higher bit depths. */
static PikaRGB
pick_color_with_gdi (POINT physical_point)
{
PikaRGB rgb;
COLORREF color;
HDC hdc;
hdc = GetDC (HWND_DESKTOP);
if (!(GetDeviceCaps (hdc, RASTERCAPS) & RC_BITBLT))
g_warning_once ("RC_BITBLT capability missing from device context");
color = GetPixel (hdc, physical_point.x, physical_point.y);
pika_rgba_set_uchar (&rgb, GetRValue (color), GetGValue (color), GetBValue (color), 255);
ReleaseDC (HWND_DESKTOP, hdc);
return rgb;
}
static void
user_picked (MonitorData *monitor,
POINT physical_point)
{
PikaRGB rgb;
GList *l;
/* Currently unused */
(void) monitor;
rgb = pick_color_with_gdi (physical_point);
for (l = pickers; l != NULL; l = l->next)
{
PikaPickButton *button = PIKA_PICK_BUTTON (l->data);
g_signal_emit_by_name (button, "color-picked", &rgb);
}
}
/* entry point to this file, called from pikapickbutton.c */
void
_pika_pick_button_win32_pick (PikaPickButton *button)
{
ensure_mouse_hook ();
ensure_keyboard_hook ();
ensure_screen_tracking ();
if (g_list_find (pickers, button))
return;
pickers = g_list_prepend (pickers,
g_object_ref (button));
}
static void
stop_picking (void)
{
remove_screen_tracking ();
remove_keyboard_hook ();
remove_mouse_hook ();
g_list_free_full (pickers, g_object_unref);
pickers = NULL;
}