implement windows clipboard functionality

This allows clipboard to operate (cut, copy, paste and delete) in the
 win32 front end. The clipboard is set and read in windows unicode
 mode and then converted to/from utf-8 for the browser core.

1 files changed, 131 insertions, 0 deletions

diff --git a/frontends/windows/clipboard.c b/frontends/windows/clipboard.c
new file mode 100644
index 000000000..bc52a4594
--- /dev/null
+++ b/frontends/windows/clipboard.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright 2019 Vincent Sanders <vince@netsurf-browser.org>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * \file
+ * win32 clipboard implementation.
+ */
+
+#include <windows.h>
+
+#include "utils/log.h"
+#include "netsurf/clipboard.h"
+
+#include "windows/clipboard.h"
+
+/**
+ * Core asks front end for clipboard contents.
+ *
+ * \param buffer UTF-8 text, allocated by front end, ownership yeilded to core
+ * \param length Byte length of UTF-8 text in buffer
+ */
+static void gui_get_clipboard(char **buffer, size_t *length)
+{
+	HANDLE clipboard_handle;
+	wchar_t *content;
+
+	if (OpenClipboard(NULL)) {
+		clipboard_handle = GetClipboardData(CF_UNICODETEXT);
+		if (clipboard_handle != NULL) {
+			content = GlobalLock(clipboard_handle);
+			if (content != NULL) {
+				int required_len;
+				size_t content_len;
+
+				content_len = wcslen(content);
+
+				/* compute length */
+				required_len = WideCharToMultiByte(
+							CP_UTF8,
+							WC_NO_BEST_FIT_CHARS,
+							content,
+							content_len,
+							NULL,
+							0,
+							NULL,
+							NULL);
+				/* allocate buffer and do conversion */
+				*buffer = malloc(required_len);
+				*length = WideCharToMultiByte(
+							CP_UTF8,
+							WC_NO_BEST_FIT_CHARS,
+							content,
+							content_len,
+							*buffer,
+							required_len,
+							NULL,
+							NULL);
+
+				GlobalUnlock(clipboard_handle);
+			}
+		}
+		CloseClipboard();
+	}
+}
+
+
+/**
+ * Core tells front end to put given text in clipboard
+ *
+ * \param buffer UTF-8 text, owned by core
+ * \param length Byte length of UTF-8 text in buffer
+ * \param styles Array of styles given to text runs, owned by core, or NULL
+ * \param n_styles Number of text run styles in array
+ */
+static void
+gui_set_clipboard(const char *buffer,
+		  size_t length,
+		  nsclipboard_styles styles[],
+		  int n_styles)
+{
+	HGLOBAL hglbCopy;
+	wchar_t *content; /* clipboard content */
+	int content_len; /* characters in content */
+
+	if (OpenClipboard(NULL)) {
+		EmptyClipboard();
+		content_len = MultiByteToWideChar(CP_UTF8,
+						  MB_PRECOMPOSED,
+						  buffer, length,
+						  NULL, 0);
+
+		hglbCopy = GlobalAlloc(GMEM_MOVEABLE,
+				       ((content_len + 1) * sizeof(wchar_t)));
+		if (hglbCopy != NULL) {
+			content = GlobalLock(hglbCopy);
+			MultiByteToWideChar(CP_UTF8,
+					    MB_PRECOMPOSED,
+					    buffer, length,
+					    content, content_len);
+			content[content_len] = 0; /* null terminate */
+
+			GlobalUnlock(hglbCopy);
+			SetClipboardData(CF_UNICODETEXT, hglbCopy);
+		}
+		CloseClipboard();
+	}
+}
+
+
+
+static struct gui_clipboard_table clipboard_table = {
+	.get = gui_get_clipboard,
+	.set = gui_set_clipboard,
+};
+
+struct gui_clipboard_table *win32_clipboard_table = &clipboard_table;