Occasionally, there is need to illustrate a point with a full program. To avoid reproducing the boring parts of the program, let’s agree on using the following template for our sample programs. <\/p>\n
For expository purposes, I won’t use a C++ class. I’ll just keep all my variables global. In a real program, of course, instance data would be attached to the window instead of floating globally. <\/p>\n
#define STRICT\n#include <windows.h>\n#include <windowsx.h>\n#include <ole2.h>\n#include <commctrl.h>\n#include <shlwapi.h>\nHINSTANCE g_hinst; \/* This application's HINSTANCE *\/\nHWND g_hwndChild; \/* Optional child window *\/\n\/*\n * OnSize\n * If we have an inner child, resize it to fit.\n *\/\nvoid\nOnSize(HWND hwnd, UINT state, int cx, int cy)\n{\n if (g_hwndChild) {\n MoveWindow(g_hwndChild, 0, 0, cx, cy, TRUE);\n }\n}\n\/*\n * OnCreate\n * Applications will typically override this and maybe even\n * create a child window.\n *\/\nBOOL\nOnCreate(HWND hwnd, LPCREATESTRUCT lpcs)\n{\n return TRUE;\n}\n\/*\n * OnDestroy\n * Post a quit message because our application is over when the\n * user closes this window.\n *\/\nvoid\nOnDestroy(HWND hwnd)\n{\n PostQuitMessage(0);\n}\n\/*\n * PaintContent\n * Interesting things will be painted here eventually.\n *\/\nvoid\nPaintContent(HWND hwnd, PAINTSTRUCT *pps)\n{\n}\n\/*\n * OnPaint\n * Paint the content as part of the paint cycle.\n *\/\nvoid\nOnPaint(HWND hwnd)\n{\n PAINTSTRUCT ps;\n BeginPaint(hwnd, &ps);\n PaintContent(hwnd, &ps);\n EndPaint(hwnd, &ps);\n}\n\/*\n * OnPrintClient\n * Paint the content as requested by USER.\n *\/\nvoid\nOnPrintClient(HWND hwnd, HDC hdc)\n{\n PAINTSTRUCT ps;\n ps.hdc = hdc;\n GetClientRect(hwnd, &ps.rcPaint);\n PaintContent(hwnd, &ps);\n}\n\/*\n * Window procedure\n *\/\nLRESULT CALLBACK\nWndProc(HWND hwnd, UINT uiMsg, WPARAM wParam, LPARAM lParam)\n{\n switch (uiMsg) {\n HANDLE_MSG(hwnd, WM_CREATE, OnCreate);\n HANDLE_MSG(hwnd, WM_SIZE, OnSize);\n HANDLE_MSG(hwnd, WM_DESTROY, OnDestroy);\n HANDLE_MSG(hwnd, WM_PAINT, OnPaint);\n case WM_PRINTCLIENT: OnPrintClient(hwnd, (HDC)wParam); return 0;\n }\n return DefWindowProc(hwnd, uiMsg, wParam, lParam);\n}\nBOOL\nInitApp(void)\n{\n WNDCLASS wc;\n wc.style = 0;\n wc.lpfnWndProc = WndProc;\n wc.cbClsExtra = 0;\n wc.cbWndExtra = 0;\n wc.hInstance = g_hinst;\n wc.hIcon = NULL;\n wc.hCursor = LoadCursor(NULL, IDC_ARROW);\n wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);\n wc.lpszMenuName = NULL;\n wc.lpszClassName = TEXT(\"Scratch\");\n if (!RegisterClass(&wc)) return FALSE;\n InitCommonControls(); \/* In case we use a common control *\/\n return TRUE;\n}\nint WINAPI WinMain(HINSTANCE hinst, HINSTANCE hinstPrev,\n LPSTR lpCmdLine, int nShowCmd)\n{\n MSG msg;\n HWND hwnd;\n g_hinst = hinst;\n if (!InitApp()) return 0;\n if (SUCCEEDED(CoInitialize(NULL))) {\/* In case we use COM *\/\n hwnd = CreateWindow(\n TEXT(\"Scratch\"), \/* Class Name *\/\n TEXT(\"Scratch\"), \/* Title *\/\n WS_OVERLAPPEDWINDOW, \/* Style *\/\n CW_USEDEFAULT, CW_USEDEFAULT, \/* Position *\/\n CW_USEDEFAULT, CW_USEDEFAULT, \/* Size *\/\n NULL, \/* Parent *\/\n NULL, \/* No menu *\/\n hinst, \/* Instance *\/\n 0); \/* No special parameters *\/\n ShowWindow(hwnd, nShowCmd);\n while (GetMessage(&msg, NULL, 0, 0)) {\n TranslateMessage(&msg);\n DispatchMessage(&msg);\n }\n CoUninitialize();\n }\n return 0;\n}\n<\/pre>\nNotice that all painting gets funneled through\nthe PaintContent<\/code> function.\nThis allows us to route\nthe WM_PRINTCLIENT<\/code> message\nthrough the same paint function,\nwhich has as an immediate consequence\nthe ability to animate the window with AnimateWindow<\/code>.\nThis will also prove useful for printing high-resolution screenshots.\n<\/p>\nOther than the trickiness with painting, there really isn’t anything here that you shouldn’t already know. The point of this program is to be a template for future programs. <\/p>\n
My first mission will be an eight-part series on scrollbars. <\/p>\n
That’s right. Scrollbars. <\/p>\n
I can’t believe I have an eight-part series on scrollbars. And you probably can’t believe you’re reading about it. <\/p>\n","protected":false},"excerpt":{"rendered":"
Occasionally, there is need to illustrate a point with a full program. To avoid reproducing the boring parts of the program, let’s agree on using the following template for our sample programs. For expository purposes, I won’t use a C++ class. I’ll just keep all my variables global. In a real program, of course, instance […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-43073","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":"
Occasionally, there is need to illustrate a point with a full program. To avoid reproducing the boring parts of the program, let’s agree on using the following template for our sample programs. For expository purposes, I won’t use a C++ class. I’ll just keep all my variables global. In a real program, of course, instance […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/43073","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=43073"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/43073\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=43073"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=43073"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=43073"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}