summaryrefslogtreecommitdiffstats
path: root/src/screensaver.cpp
blob: 75e6ba54355ec77bceeb5469d535ee1ec149d802 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
#include "screensaver.h"

#include <QX11Info>
#include <QStringList>
#include <QProcess>
#include <X11/Xlib.h>
#include <X11/Xatom.h>

#ifdef X11_Xscreensaver_FOUND
#include <X11/extensions/scrnsaver.h>
#include <X11/Xutil.h>
#endif
#ifdef X11_dpms_FOUND
#include <X11/extensions/dpms.h>
#endif

namespace {

Display *display = nullptr;
bool extensionSupported = false;
bool dpmsSupported = false;
Atom XA_SCREENSAVER_VERSION, XA_SCREENSAVER_STATUS, XA_LOCK;
XErrorHandler old_handler = nullptr;
Bool got_badwindow = False;

bool init()
{
    if (display != nullptr) {
        return true;
    }
    display = QX11Info::display();
    if (display == nullptr) {
        return false;
    }
#ifdef X11_Xscreensaver_FOUND
    int dummy;
    extensionSupported = (XScreenSaverQueryExtension(display, &dummy, &dummy) == True);
    if (extensionSupported) {
        XA_SCREENSAVER_STATUS = XInternAtom( display, "_SCREENSAVER_STATUS", False );
        XA_SCREENSAVER_VERSION = XInternAtom( display, "_SCREENSAVER_VERSION",False );
        XA_LOCK = XInternAtom( display, "LOCK", False );
    }
#endif
#ifdef X11_dpms_FOUND
    dpmsSupported = (DPMSCapable(display) == True);
#endif
    return true;
}

static int BadWindow_ehandler( Display *dpy, XErrorEvent *error )
{
    if( error->error_code == BadWindow ) {
        got_badwindow = True;
        return 0;
    } else {
        if( !old_handler ) {
            abort();
        }
        return ( *old_handler )( dpy, error );
    }
}

#ifdef X11_Xscreensaver_FOUND
static Window find_screensaver_window( Display *dpy, char **version )
{
    unsigned int i;
    Window root = RootWindowOfScreen( DefaultScreenOfDisplay( dpy ) );
    Window root2, parent, *kids;
    unsigned int nkids;

    if( version ) {
        *version = 0;
    }

    if( ! XQueryTree( dpy, root, &root2, &parent, &kids, &nkids ) ) {
        abort();
    }
    if( root != root2 ) {
        abort();
    }
    if( parent ) {
        abort();
    }
    if( !( kids && nkids ) ) {
        return 0;
    }
    for( i = 0; i < nkids; i++ ) {
        Atom type;
        int format;
        unsigned long nitems, bytesafter;
        unsigned char *v;
        int status;

        /* We're walking the list of root-level windows and trying to find
               the one that has a particular property on it.  We need to trap
               BadWindows errors while doing this, because it's possible that
               some random window might get deleted in the meantime.  (That
               window won't have been the one we're looking for.)
             */
        XSync( dpy, False );
        if( old_handler ) {
            abort();
        }
        got_badwindow = False;
        old_handler = XSetErrorHandler( BadWindow_ehandler );
        status = XGetWindowProperty( dpy, kids[i],
                                     XA_SCREENSAVER_VERSION,
                                     0, 200, False, XA_STRING,
                                     &type, &format, &nitems, &bytesafter,
                                     &v );
        XSync( dpy, False );
        XSetErrorHandler( old_handler );
        old_handler = nullptr;

        if( got_badwindow ) {
            status = BadWindow;
            got_badwindow = False;
        }

        if( status == Success && type != None ) {
            Window ret = kids[i];
            if( version ) {
                *version = ( char* )v;
            }
            XFree( kids );
            return ret;
        }
    }

    if( kids ) {
        XFree( kids );
    }
    return 0;
}
#endif

}

/*
 * Main attraction
 */

namespace ScreenSaver {

void allowSaverAndStandby(bool allow)
{
    if (!init())
        return;
#ifdef X11_Xscreensaver_FOUND
    if (extensionSupported) {
        XScreenSaverSuspend(display, allow ? False : True);
        return;
    }
#endif
    // TODO: Maybe try some fallback, call xset, or trigger some event periodically
}

void forceScreenOn()
{
    if (!init())
        return;
#ifdef X11_dpms_FOUND
    CARD16 power_level;
    BOOL state;
    if (DPMSInfo(display, &power_level, &state) && state) {
        DPMSForceLevel(display, DPMSModeOn);
        return;
    }
#endif
}

bool isLocked()
{
#ifdef X11_Xscreensaver_FOUND
    if (!init())
        return false;
    char *v = nullptr;
    Window window = find_screensaver_window( display, &v );
    if( !window )
        return false;
    if( !v || !*v )
        return false;
    XClassHint hint;
    memset( &hint, 0, sizeof( hint ) );
    XGetClassHint( display, window, &hint );
    if( !hint.res_class )
        return false;

    Atom type;
    int format;
    unsigned long nitems, bytesafter;
    Atom *data = nullptr;
    if( XGetWindowProperty( display,
                            RootWindow( display, 0 ),
                            XA_SCREENSAVER_STATUS,
                            0, 999, False, XA_INTEGER,
                            &type, &format, &nitems, &bytesafter,
                            reinterpret_cast<unsigned char**>(&data) )
            != Success
            || !type
            || data == nullptr )
        return false;
    if( type != XA_INTEGER || nitems < 3 ) {
        if( data ) {
            free( data );
        }
        return false;
    }

    Atom blanked = ( Atom ) data[0];
    if( blanked == XA_LOCK )
        return true; // Yay
#endif
    return false;
}

}