...in with the new.

1 files changed, 500 insertions, 0 deletions

diff --git a/area_windows.c b/area_windows.c
new file mode 100644
index 0000000..b8f1235
--- /dev/null
+++ b/area_windows.c
@@ -0,0 +1,500 @@
+// 24 march 2014
+
+#include "winapi_windows.h"
+#include "_cgo_export.h"
+
+static void getScrollPos(HWND hwnd, int *xpos, int *ypos)
+{
+	SCROLLINFO si;
+
+	ZeroMemory(&si, sizeof (SCROLLINFO));
+	si.cbSize = sizeof (SCROLLINFO);
+	si.fMask = SIF_POS | SIF_TRACKPOS;
+	if (GetScrollInfo(hwnd, SB_HORZ, &si) == 0)
+		xpanic("error getting horizontal scroll position for Area", GetLastError());
+	*xpos = si.nPos;
+	// MSDN example code reinitializes this each time, so we'll do it too just to be safe
+	ZeroMemory(&si, sizeof (SCROLLINFO));
+	si.cbSize = sizeof (SCROLLINFO);
+	si.fMask = SIF_POS | SIF_TRACKPOS;
+	if (GetScrollInfo(hwnd, SB_VERT, &si) == 0)
+		xpanic("error getting vertical scroll position for Area", GetLastError());
+	*ypos = si.nPos;
+}
+
+#define areaBackgroundBrush ((HBRUSH) (COLOR_BTNFACE + 1))
+
+static void paintArea(HWND hwnd, void *data)
+{
+	RECT xrect;
+	PAINTSTRUCT ps;
+	HDC hdc;
+	HDC rdc;
+	HBITMAP rbitmap, prevrbitmap;
+	RECT rrect;
+	BITMAPINFO bi;
+	VOID *ppvBits;
+	HBITMAP ibitmap;
+	HDC idc;
+	HBITMAP previbitmap;
+	BLENDFUNCTION blendfunc;
+	void *i;
+	intptr_t dx, dy;
+	int hscroll, vscroll;
+
+	// FALSE here indicates don't send WM_ERASEBKGND
+	if (GetUpdateRect(hwnd, &xrect, FALSE) == 0)
+		return;		// no update rect; do nothing
+
+	getScrollPos(hwnd, &hscroll, &vscroll);
+
+	hdc = BeginPaint(hwnd, &ps);
+	if (hdc == NULL)
+		xpanic("error beginning Area repaint", GetLastError());
+
+	// very big thanks to Ninjifox for suggesting this technique and helping me go through it
+
+	// first let's create the destination image, which we fill with the windows background color
+	// this is how we fake drawing the background; see also http://msdn.microsoft.com/en-us/library/ms969905.aspx
+	rdc = CreateCompatibleDC(hdc);
+	if (rdc == NULL)
+		xpanic("error creating off-screen rendering DC", GetLastError());
+	// the bitmap has to be compatible with the window
+	// if we create a bitmap compatible with the DC we just created, it'll be monochrome
+	// thanks to David Heffernan in http://stackoverflow.com/questions/23033636/winapi-gdi-fillrectcolor-btnface-fills-with-strange-grid-like-brush-on-window
+	rbitmap = CreateCompatibleBitmap(hdc, xrect.right - xrect.left, xrect.bottom - xrect.top);
+	if (rbitmap == NULL)
+		xpanic("error creating off-screen rendering bitmap", GetLastError());
+	prevrbitmap = (HBITMAP) SelectObject(rdc, rbitmap);
+	if (prevrbitmap == NULL)
+		xpanic("error connecting off-screen rendering bitmap to off-screen rendering DC", GetLastError());
+	rrect.left = 0;
+	rrect.right = xrect.right - xrect.left;
+	rrect.top = 0;
+	rrect.bottom = xrect.bottom - xrect.top;
+	if (FillRect(rdc, &rrect, areaBackgroundBrush) == 0)
+		xpanic("error filling off-screen rendering bitmap with the system background color", GetLastError());
+
+	i = doPaint(&xrect, hscroll, vscroll, data, &dx, &dy);
+	if (i == NULL)			// cliprect empty
+		goto nobitmap;		// we need to blit the background no matter what
+
+	// now we need to shove realbits into a bitmap
+	// technically bitmaps don't know about alpha; they just ignore the alpha byte
+	// AlphaBlend(), however, sees it - see http://msdn.microsoft.com/en-us/library/windows/desktop/dd183352%28v=vs.85%29.aspx
+	ZeroMemory(&bi, sizeof (BITMAPINFO));
+	bi.bmiHeader.biSize = sizeof (BITMAPINFOHEADER);
+	bi.bmiHeader.biWidth = (LONG) dx;
+	bi.bmiHeader.biHeight = -((LONG) dy);			// negative height to force top-down drawing;
+	bi.bmiHeader.biPlanes = 1;
+	bi.bmiHeader.biBitCount = 32;
+	bi.bmiHeader.biCompression = BI_RGB;
+	bi.bmiHeader.biSizeImage = (DWORD) (dx * dy * 4);
+	// this is all we need, but because this confused me at first, I will say the two pixels-per-meter fields are unused (see http://blogs.msdn.com/b/oldnewthing/archive/2013/05/15/10418646.aspx and page 581 of Charles Petzold's Programming Windows, Fifth Edition)
+	// now for the trouble: CreateDIBSection() allocates the memory for us...
+	ibitmap = CreateDIBSection(NULL,		// Ninjifox does this, so do some wine tests (http://source.winehq.org/source/dlls/gdi32/tests/bitmap.c#L725, thanks vpovirk in irc.freenode.net/#winehackers) and even Raymond Chen (http://blogs.msdn.com/b/oldnewthing/archive/2006/11/16/1086835.aspx), so.
+		&bi, DIB_RGB_COLORS, &ppvBits, 0, 0);
+	if (ibitmap == NULL)
+		xpanic("error creating HBITMAP for image returned by AreaHandler.Paint()", GetLastError());
+
+	// now we have to do TWO MORE things before we can finally do alpha blending
+	// first, we need to load the bitmap memory, because Windows makes it for us
+	// the pixels are arranged in RGBA order, but GDI requires BGRA
+	// this turns out to be just ARGB in little endian; let's convert into this memory
+	dotoARGB(i, (void *) ppvBits, FALSE);		// FALSE = not NRGBA
+
+	// the second thing is... make a device context for the bitmap :|
+	// Ninjifox just makes another compatible DC; we'll do the same
+	idc = CreateCompatibleDC(hdc);
+	if (idc == NULL)
+		xpanic("error creating HDC for image returned by AreaHandler.Paint()", GetLastError());
+	previbitmap = (HBITMAP) SelectObject(idc, ibitmap);
+	if (previbitmap == NULL)
+		xpanic("error connecting HBITMAP for image returned by AreaHandler.Paint() to its HDC", GetLastError());
+
+	// AND FINALLY WE CAN DO THE ALPHA BLENDING!!!!!!111
+	blendfunc.BlendOp = AC_SRC_OVER;
+	blendfunc.BlendFlags = 0;
+	blendfunc.SourceConstantAlpha = 255;		// only use per-pixel alphas
+	blendfunc.AlphaFormat = AC_SRC_ALPHA;	// premultiplied
+	if (AlphaBlend(rdc, 0, 0, (int) dx, (int) dy,		// destination
+		idc, 0, 0, (int) dx, (int)dy,				// source
+		blendfunc) == FALSE)
+		xpanic("error alpha-blending image returned by AreaHandler.Paint() onto background", GetLastError());
+
+	// clean up after idc/ibitmap here because of the goto nobitmap
+	if (SelectObject(idc, previbitmap) != ibitmap)
+		xpanic("error reverting HDC for image returned by AreaHandler.Paint() to original HBITMAP", GetLastError());
+	if (DeleteObject(ibitmap) == 0)
+		xpanic("error deleting HBITMAP for image returned by AreaHandler.Paint()", GetLastError());
+	if (DeleteDC(idc) == 0)
+		xpanic("error deleting HDC for image returned by AreaHandler.Paint()", GetLastError());
+
+nobitmap:
+	// and finally we can just blit that into the window
+	if (BitBlt(hdc, xrect.left, xrect.top, xrect.right - xrect.left, xrect.bottom - xrect.top,
+		rdc, 0, 0,			// from the rdc's origin
+		SRCCOPY) == 0)
+		xpanic("error blitting Area image to Area", GetLastError());
+
+	// now to clean up
+	if (SelectObject(rdc, prevrbitmap) != rbitmap)
+		xpanic("error reverting HDC for off-screen rendering to original HBITMAP", GetLastError());
+	if (DeleteObject(rbitmap) == 0)
+		xpanic("error deleting HBITMAP for off-screen rendering", GetLastError());
+	if (DeleteDC(rdc) == 0)
+		xpanic("error deleting HDC for off-screen rendering", GetLastError());
+
+	EndPaint(hwnd, &ps);
+}
+
+static SIZE getAreaControlSize(HWND hwnd)
+{
+	RECT rect;
+	SIZE size;
+
+	if (GetClientRect(hwnd, &rect) == 0)
+		xpanic("error getting size of actual Area control", GetLastError());
+	size.cx = (LONG) (rect.right - rect.left);
+	size.cy = (LONG) (rect.bottom - rect.top);
+	return size;
+}
+
+static void scrollArea(HWND hwnd, void *data, WPARAM wParam, int which)
+{
+	SCROLLINFO si;
+	SIZE size;
+	LONG cwid, cht;
+	LONG pagesize, maxsize;
+	LONG newpos;
+	LONG delta;
+	LONG dx, dy;
+
+	size = getAreaControlSize(hwnd);
+	cwid = size.cx;
+	cht = size.cy;
+	if (which == SB_HORZ) {
+		pagesize = cwid;
+		maxsize = areaWidthLONG(data);
+	} else if (which == SB_VERT) {
+		pagesize = cht;
+		maxsize = areaHeightLONG(data);
+	} else
+		xpanic("invalid which sent to scrollArea()", 0);
+
+	ZeroMemory(&si, sizeof (SCROLLINFO));
+	si.cbSize = sizeof (SCROLLINFO);
+	si.fMask = SIF_POS | SIF_TRACKPOS;
+	if (GetScrollInfo(hwnd, which, &si) == 0)
+		xpanic("error getting current scroll position for scrolling", GetLastError());
+
+	newpos = (LONG) si.nPos;
+	switch (LOWORD(wParam)) {
+	case SB_LEFT:			// also SB_TOP; C won't let me have both (C89 §6.6.4.2; C99 §6.8.4.2)
+		newpos = 0;
+		break;
+	case SB_RIGHT:		// also SB_BOTTOM
+		// see comment in adjustAreaScrollbars() below
+		newpos = maxsize - pagesize;
+		break;
+	case SB_LINELEFT:		// also SB_LINEUP
+		newpos--;
+		break;
+	case SB_LINERIGHT:		// also SB_LINEDOWN
+		newpos++;
+		break;
+	case SB_PAGELEFT:		// also SB_PAGEUP
+		newpos -= pagesize;
+		break;
+	case SB_PAGERIGHT:	// also SB_PAGEDOWN
+		newpos += pagesize;
+		break;
+	case SB_THUMBPOSITION:
+		// raymond chen says to just set the newpos to the SCROLLINFO nPos for this message; see http://blogs.msdn.com/b/oldnewthing/archive/2003/07/31/54601.aspx and http://blogs.msdn.com/b/oldnewthing/archive/2003/08/05/54602.aspx
+		// do nothing here; newpos already has nPos
+		break;
+	case SB_THUMBTRACK:
+		newpos = (LONG) si.nTrackPos;
+	}
+	// otherwise just keep the current position (that's what MSDN example code says, anyway)
+
+	// make sure we're not out of range
+	if (newpos < 0)
+		newpos = 0;
+	if (newpos > (maxsize - pagesize))
+		newpos = maxsize - pagesize;
+
+	// this would be where we would put a check to not scroll if the scroll position changed, but see the note about SB_THUMBPOSITION above: Raymond Chen's code always does the scrolling anyway in this case
+
+	delta = -(newpos - si.nPos);		// negative because ScrollWindowEx() scrolls in the opposite direction
+	dx = delta;
+	dy = 0;
+	if (which == SB_VERT) {
+		dx = 0;
+		dy = delta;
+	}
+
+	// this automatically scrolls the edit control, if any
+	if (ScrollWindowEx(hwnd,
+		(int) dx, (int) dy,
+		// these four change what is scrolled and record info about the scroll; we're scrolling the whole client area and don't care about the returned information here
+		NULL, NULL, NULL, NULL,
+		// mark the remaining rect as needing redraw and erase...
+		SW_INVALIDATE | SW_ERASE) == ERROR)
+			xpanic("error scrolling Area", GetLastError());
+	// ...but don't redraw the window yet; we need to apply our scroll changes
+
+	// we actually have to commit the change back to the scrollbar; otherwise the scroll position will merely reset itself
+	ZeroMemory(&si, sizeof (SCROLLINFO));
+	si.cbSize = sizeof (SCROLLINFO);
+	si.fMask = SIF_POS;
+	si.nPos = (int) newpos;
+	// this is not expressly documented as returning an error so IDK what the error code is so assume there is none
+	SetScrollInfo(hwnd, which, &si, TRUE);		// redraw scrollbar
+
+	// NOW redraw it
+	if (UpdateWindow(hwnd) == 0)
+		xpanic("error updating Area after scrolling", GetLastError());
+	if ((HWND) GetWindowLongPtrW(hwnd, 0) != NULL)
+		if (UpdateWindow((HWND) GetWindowLongPtrW(hwnd, 0)) == 0)
+			xpanic("error updating Area TextField after scrolling", GetLastError());
+}
+
+static void adjustAreaScrollbars(HWND hwnd, void *data)
+{
+	SCROLLINFO si;
+	SIZE size;
+	LONG cwid, cht;
+
+	size = getAreaControlSize(hwnd);
+	cwid = size.cx;
+	cht = size.cy;
+
+	// the trick is we want a page to be the width/height of the visible area
+	// so the scroll range would go from [0..image_dimension - control_dimension]
+	// but judging from the sample code on MSDN, we don't need to do this; the scrollbar will do it for us
+	// we DO need to handle it when scrolling, though, since the thumb can only go up to this upper limit
+
+	// have to do horizontal and vertical separately
+	ZeroMemory(&si, sizeof (SCROLLINFO));
+	si.cbSize = sizeof (SCROLLINFO);
+	si.fMask = SIF_RANGE | SIF_PAGE;
+	si.nMin = 0;
+	si.nMax = (int) (areaWidthLONG(data) - 1);		// the max point is inclusive, so we have to pass in the last valid value, not the first invalid one (see http://blogs.msdn.com/b/oldnewthing/archive/2003/07/31/54601.aspx); if we don't, we get weird things like the scrollbar sometimes showing one extra scroll position at the end that you can never scroll to
+	si.nPage = (UINT) cwid;
+	SetScrollInfo(hwnd, SB_HORZ, &si, TRUE);		// redraw the scroll bar
+
+	// MSDN sample code does this a second time; let's do it too to be safe
+	ZeroMemory(&si, sizeof (SCROLLINFO));
+	si.cbSize = sizeof (SCROLLINFO);
+	si.fMask = SIF_RANGE | SIF_PAGE;
+	si.nMin = 0;
+	si.nMax = (int) (areaHeightLONG(data) - 1);
+	si.nPage = (UINT) cht;
+	SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
+}
+
+void repaintArea(HWND hwnd, RECT *r)
+{
+	// NULL - the whole area; TRUE - have windows erase if possible
+	if (InvalidateRect(hwnd, r, TRUE) == 0)
+		xpanic("error flagging Area as needing repainting after event", GetLastError());
+	if (UpdateWindow(hwnd) == 0)
+		xpanic("error repainting Area after event", GetLastError());
+}
+
+void areaMouseEvent(HWND hwnd, void *data, DWORD button, BOOL up, uintptr_t heldButtons, LPARAM lParam)
+{
+	int xpos, ypos;
+
+	// mouse coordinates are relative to control; make them relative to Area
+	getScrollPos(hwnd, &xpos, &ypos);
+	xpos += GET_X_LPARAM(lParam);
+	ypos += GET_Y_LPARAM(lParam);
+	finishAreaMouseEvent(data, button, up, heldButtons, xpos, ypos);
+}
+
+static LRESULT CALLBACK areaWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+	void *data;
+	DWORD which;
+	uintptr_t heldButtons = (uintptr_t) wParam;
+	LRESULT lResult;
+
+	data = getWindowData(hwnd, uMsg, wParam, lParam, &lResult, storeAreaHWND);
+	if (data == NULL)
+		return lResult;
+	switch (uMsg) {
+	case WM_PAINT:
+		paintArea(hwnd, data);
+		return 0;
+	case WM_ERASEBKGND:
+		// don't draw a background; we'll do so when painting
+		// this is to make things flicker-free; see http://msdn.microsoft.com/en-us/library/ms969905.aspx
+		return 1;
+	case WM_HSCROLL:
+		scrollArea(hwnd, data, wParam, SB_HORZ);
+		return 0;
+	case WM_VSCROLL:
+		scrollArea(hwnd, data, wParam, SB_VERT);
+		return 0;
+	case WM_SIZE:
+		adjustAreaScrollbars(hwnd, data);
+		return 0;
+	case WM_ACTIVATE:
+		// don't keep the double-click timer running if the user switched programs in between clicks
+		areaResetClickCounter(data);
+		return 0;
+	case WM_MOUSEMOVE:
+		areaMouseEvent(hwnd, data, 0, FALSE, heldButtons, lParam);
+		return 0;
+	case WM_LBUTTONDOWN:
+		SetFocus(hwnd);
+		areaMouseEvent(hwnd, data, 1, FALSE, heldButtons, lParam);
+		return 0;
+	case WM_LBUTTONUP:
+		areaMouseEvent(hwnd, data, 1, TRUE, heldButtons, lParam);
+		return 0;
+	case WM_MBUTTONDOWN:
+		SetFocus(hwnd);
+		areaMouseEvent(hwnd, data, 2, FALSE, heldButtons, lParam);
+		return 0;
+	case WM_MBUTTONUP:
+		areaMouseEvent(hwnd, data, 2, TRUE, heldButtons, lParam);
+		return 0;
+	case WM_RBUTTONDOWN:
+		SetFocus(hwnd);
+		areaMouseEvent(hwnd, data, 3, FALSE, heldButtons, lParam);
+		return 0;
+	case WM_RBUTTONUP:
+		areaMouseEvent(hwnd, data, 3, TRUE, heldButtons, lParam);
+		return 0;
+	case WM_XBUTTONDOWN:
+		SetFocus(hwnd);
+		// values start at 1; we want them to start at 4
+		which = (DWORD) GET_XBUTTON_WPARAM(wParam) + 3;
+		heldButtons = (uintptr_t) GET_KEYSTATE_WPARAM(wParam);
+		areaMouseEvent(hwnd, data, which, FALSE, heldButtons, lParam);
+		return TRUE;		// XBUTTON messages are different!
+	case WM_XBUTTONUP:
+		which = (DWORD) GET_XBUTTON_WPARAM(wParam) + 3;
+		heldButtons = (uintptr_t) GET_KEYSTATE_WPARAM(wParam);
+		areaMouseEvent(hwnd, data, which, TRUE, heldButtons, lParam);
+		return TRUE;
+	case msgAreaKeyDown:
+		return (LRESULT) areaKeyEvent(data, FALSE, wParam, lParam);
+	case msgAreaKeyUp:
+		return (LRESULT) areaKeyEvent(data, TRUE, wParam, lParam);
+	case msgAreaSizeChanged:
+		adjustAreaScrollbars(hwnd, data);
+		repaintArea(hwnd, NULL);		// this calls for an update
+		return 0;
+	case msgAreaGetScroll:
+		getScrollPos(hwnd, (int *) wParam, (int *) lParam);
+		return 0;
+	case msgAreaRepaint:
+		repaintArea(hwnd, (RECT *) lParam);
+		return 0;
+	case msgAreaRepaintAll:
+		repaintArea(hwnd, NULL);
+		return 0;
+	default:
+		return DefWindowProcW(hwnd, uMsg, wParam, lParam);
+	}
+	xmissedmsg("Area", "areaWndProc()", uMsg);
+	return 0;			// unreached
+}
+
+DWORD makeAreaWindowClass(char **errmsg)
+{
+	WNDCLASSW wc;
+
+	ZeroMemory(&wc, sizeof (WNDCLASSW));
+	wc.style = CS_HREDRAW | CS_VREDRAW;			// no CS_DBLCLKS because do that manually
+	wc.lpszClassName = areaWindowClass;
+	wc.lpfnWndProc = areaWndProc;
+	wc.hInstance = hInstance;
+	wc.hIcon = hDefaultIcon;
+	wc.hCursor = hArrowCursor,
+	wc.hbrBackground = NULL;				// no brush; we handle WM_ERASEBKGND
+	wc.cbWndExtra = 3 * sizeof (LONG_PTR);		// text field handle, text field current x, text field current y
+	if (RegisterClassW(&wc) == 0) {
+		*errmsg = "error registering Area window class";
+		return GetLastError();
+	}
+	return 0;
+}
+
+HWND newArea(void *data)
+{
+	HWND hwnd;
+
+	hwnd = CreateWindowExW(
+		0,
+		areaWindowClass, L"",
+		WS_HSCROLL | WS_VSCROLL | WS_CHILD | WS_VISIBLE | WS_TABSTOP,
+		CW_USEDEFAULT, CW_USEDEFAULT,
+		100, 100,
+		msgwin, NULL, hInstance, data);
+	if (hwnd == NULL)
+		xpanic("container creation failed", GetLastError());
+	return hwnd;
+}
+
+static LRESULT CALLBACK areaTextFieldSubProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR id, DWORD_PTR data)
+{
+	switch (uMsg) {
+	case WM_KILLFOCUS:
+		ShowWindow(hwnd, SW_HIDE);
+		areaTextFieldDone((void *) data);
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
+	case WM_NCDESTROY:
+		if ((*fv_RemoveWindowSubclass)(hwnd, areaTextFieldSubProc, id) == FALSE)
+			xpanic("error removing Area TextField subclass (which was for handling WM_KILLFOCUS)", GetLastError());
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
+	default:
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
+	}
+	xmissedmsg("Area TextField", "areaTextFieldSubProc()", uMsg);
+	return 0;		// unreached
+}
+
+HWND newAreaTextField(HWND area, void *goarea)
+{
+	HWND tf;
+
+	tf = CreateWindowExW(textfieldExtStyle,
+		L"edit", L"",
+		textfieldStyle | WS_CHILD,
+		0, 0, 0, 0,
+		area, NULL, hInstance, NULL);
+	if (tf == NULL)
+		xpanic("error making Area TextField", GetLastError());
+	if ((*fv_SetWindowSubclass)(tf, areaTextFieldSubProc, 0, (DWORD_PTR) goarea) == FALSE)
+		xpanic("error subclassing Area TextField to give it its own WM_KILLFOCUS handler", GetLastError());
+	return tf;
+}
+
+void areaOpenTextField(HWND area, HWND textfield, int x, int y, int width, int height)
+{
+	int sx, sy;
+	int baseX, baseY;
+	LONG unused;
+
+	getScrollPos(area, &sx, &sy);
+	x += sx;
+	y += sy;
+	calculateBaseUnits(textfield, &baseX, &baseY, &unused);
+	width = MulDiv(width, baseX, 4);
+	height = MulDiv(height, baseY, 8);
+	if (MoveWindow(textfield, x, y, width, height, TRUE) == 0)
+		xpanic("error moving Area TextField in Area.OpenTextFieldAt()", GetLastError());
+	ShowWindow(textfield, SW_SHOW);
+	if (SetFocus(textfield) == NULL)
+		xpanic("error giving Area TextField focus", GetLastError());
+}
+
+void areaMarkTextFieldDone(HWND area)
+{
+	SetWindowLongPtrW(area, 0, (LONG_PTR) NULL);
+}