Start work on helper process for windows file dialogs

2026-05-21 14:26:33 -04:00 · 2016-05-03 18:26:51 +05:30
parent f451b173ed
commit d8fe21d156
2 changed files with 169 additions and 0 deletions
@@ -0,0 +1,79 @@
+/*
+ * file_dialogs.c
+ * Copyright (C) 2016 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include <Windows.h>
+#include <Shobjidl.h>
+#include <stdio.h>
+#include <string.h>
+
+#define PRINTERR(x) fprintf(stderr, x); fflush(stderr);
+#define REPORTERR(x) { PRINTERR(x); ret = 1; goto error; }
+#define CALLCOM(x, err) hr = x; if(FAILED(hr)) REPORTERR(err)
+
+int show_dialog(HWND parent, bool save_dialog) {
+	int ret = 0;
+	IFileDialog *pfd = NULL;
+	IShellItem *psiResult = NULL;
+	DWORD dwFlags;
+	HRESULT hr = S_OK;
+	hr = CoInitialize(NULL);
+	if (FAILED(hr)) { PRINTERR("Failed to initialize COM"); return 1; }
+
+	CALLCOM(CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_INPROC_SERVER, (save_dialog ? IID_IFileSaveDialog : IID_IFileOpenDialog), reinterpret_cast<LPVOID*>(&pfd)), "Failed to create COM object for file dialog")
+	CALLCOM(pfd->GetOptions(&dwFlags), "Failed to get options")
+	dwFlags |= FOS_FORCEFILESYSTEM;
+	CALLCOM(pfd->SetOptions(dwFlags), "Failed to set options")
+	hr = pfd->Show(parent);
+	if (hr == HRESULT_FROM_WIN32(ERROR_CANCELLED)) goto error;
+	if (FAILED(hr)) REPORTERR("Failed to show dialog")
+
+	CALLCOM(pfd->GetResult(&psiResult), "Failed to get dialog result")
+
+error:
+	if(pfd) pfd->Release();
+	CoUninitialize();
+	return ret;
+}
+
+bool read_bytes(size_t sz, char* buf, bool allow_incomplete=false) {
+	char *ptr = buf, *limit = buf + sz;
+	while(limit > ptr && !feof(stdin) && !ferror(stdin)) {
+		ptr += fread(ptr, 1, limit - ptr, stdin);
+	}
+	if (ferror(stdin)) { PRINTERR("Failed to read from stdin!"); return false; }
+	if (ptr - buf != sz) { if (!allow_incomplete) PRINTERR("Truncated input!"); return false; }
+	return true;
+}
+
+#define READ(x, y) if (!read_bytes((x), (y))) return 1;
+
+int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow) {
+	char buf[257];
+	size_t key_size = 0;
+	HWND parent = NULL;
+	bool save_dialog = false;
+
+	while(!feof(stdin)) {
+		memset(buf, 0, sizeof(buf));
+		if(!read_bytes(1, buf, true)) { if (feof(stdin)) break; return 1;}
+		key_size = (size_t)buf[0];
+		READ(key_size, buf);
+		if (key_size == 4 && memcmp(buf, "HWND", 4) == 0) {
+			READ(sizeof(HWND), buf);
+			if (sizeof(HWND) == 8) parent = (HWND)*((__int64*)buf);
+			else if (sizeof(HWND) == 4) parent = (HWND)*((__int32*)buf);
+			else { fprintf(stderr, "Unknown pointer size: %d", sizeof(HWND)); return 1;}
+		}
+
+		else {
+			PRINTERR("Unknown key");
+			return 1;
+		}
+	}
+
+	return show_dialog(parent, save_dialog);
+}