aboutsummaryrefslogtreecommitdiff
path: root/c/common.cpp
blob: 59f0fdca79f1325e705e758d8e64c4a46898a760 (plain)
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
#include <utility>
#include <windows.h>

#include "common.h"

/* wchar_ptr: Simple wrapper for wide C strings. */

wchar_ptr::wchar_ptr() {}

wchar_ptr::wchar_ptr(wchar_t* const s) : m_p(s) {}

wchar_ptr& wchar_ptr::operator=(wchar_t* const s)
{
	if (m_p != s) {
		delete m_p;
		m_p = s;
	}
	return *this;
}

wchar_ptr::wchar_ptr(wchar_ptr&& other) noexcept : m_p(std::exchange(other.m_p, nullptr)) {}

wchar_ptr& wchar_ptr::operator=(wchar_ptr&& other) noexcept
{
	std::swap(m_p, other.m_p);
	return *this;
}

wchar_ptr::operator wchar_t*() noexcept
{
	return m_p;
}

/* Return pointer, releasing ownership. */
wchar_t* wchar_ptr::release()
{
	wchar_t* p2 = m_p;
	m_p = nullptr;
	return p2;
}

wchar_ptr::~wchar_ptr()
{
	delete m_p;
}

wchar_ptr wchar_ptr::from_narrow(const char* const src, const int cp)
{
	int cbMultiByte = strlen(src)+1;
	int cchWideChar = MultiByteToWideChar(cp, 0, src, cbMultiByte, NULL, 0);
	wchar_t* dst = new wchar_t[cchWideChar];
	if (!MultiByteToWideChar(cp, 0, src, cbMultiByte, dst, cchWideChar)) {
		delete dst;
		throw Win32Error();
	}
	return dst;
}

wchar_ptr wchar_ptr::copy(const wchar_t* const src)
{
	const int cb = wcslen(src)+1;
	wchar_t* dst = new wchar_t[cb];
	memcpy(dst, src, cb*sizeof(wchar_t));
	return dst;
}

/* Win32Error: Exception for Windows API errors. */

Win32Error::Win32Error() : code(GetLastError()) {}
Win32Error::Win32Error(const DWORD code) : code(code) {}

Win32Error::~Win32Error()
{
	if (m_szMsg)
		HeapFree(GetProcessHeap(), 0, m_szMsg);
	if (m_wszMsg)
		HeapFree(GetProcessHeap(), 0, m_wszMsg);
}

const char* Win32Error::what() const noexcept
{
	if (!m_szMsg)
		FormatMessageA(
		    FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
		    NULL,
		    code,
		    MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
		    (char*)&m_szMsg,
		    0, NULL);
	return m_szMsg;
}

const wchar_t* Win32Error::WhatW() const noexcept
{
	if (!m_wszMsg)
		FormatMessage(
		    FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
		    NULL,
		    code,
		    MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
		    (wchar_t*)&m_wszMsg,
		    0, NULL);
	return m_wszMsg;
}

/* Library: Wrapper for loading and freeing dynamically linked libraries. */

std::optional<Library> Library::Maybe(const wchar_t* const lib)
{
	HMODULE hModule = LoadLibrary(lib);
	if (!hModule) return {};
	return Library(hModule);
}

Library::Library(const HMODULE hModule) : m_hModule(hModule) {}

Library::Library(const wchar_t* const lib)
{
	m_hModule = LoadLibrary(lib);
	if (!m_hModule)
		throw Win32Error();
}

Library::~Library()
{
	FreeLibrary(m_hModule);
}

/* Show message box owned by and centered in the main window. */
int EBMessageBox(const wchar_t* const wszText, const wchar_t* const wszCaption, const unsigned uType)
{
	extern HWND g_hWnd;

	auto proc = [](const int nCode, const WPARAM wParam, const LPARAM lParam) noexcept
		-> LRESULT CALLBACK
	{
		if (!g_hWnd || nCode < 0 || nCode != HCBT_ACTIVATE)
			return CallNextHookEx(0, nCode, wParam, lParam);

		HWND hWnd = (HWND)wParam;
		long lStyle = GetWindowLong(hWnd, GWL_STYLE);
		if (!(lStyle & WS_POPUP)) return 0;

		RECT rcMain, rcMsg;
		GetWindowRect(g_hWnd, &rcMain);
		GetWindowRect(hWnd, &rcMsg);
		SetWindowPos(hWnd, NULL,
		    rcMain.left+(rcMain.right-rcMain.left)/2-(rcMsg.right-rcMsg.left)/2,
		    rcMain.top+(rcMain.bottom-rcMain.top)/2-(rcMsg.bottom-rcMsg.top)/2,
		    -1, -1,
		    SWP_NOZORDER|SWP_NOSIZE|SWP_NOACTIVATE);

		return 0;
	};

	HHOOK hHook = require(SetWindowsHookEx(WH_CBT, proc, (HINSTANCE)NULL, GetCurrentThreadId()));
	int r = MessageBox(g_hWnd, wszText, wszCaption, uType);
	require(UnhookWindowsHookEx(hHook));
	return r;
}

int GetRelativeCursorPos(HWND hWnd, POINT* pt)
{
	RECT rc;
	if (!GetClientRect(hWnd, &rc)) return 0;
	SetLastError(ERROR_SUCCESS);
	if (!MapWindowPoints(hWnd, NULL, (POINT*)&rc, 2)) return 0;

	POINT ptMouse;
	if (!GetCursorPos(&ptMouse)) return 0;
	pt->x = ptMouse.x-rc.left;
	pt->y = ptMouse.y-rc.top;
	return 1;
}