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I am currently subclassing a ListView control to support custom color schemes - especially Dark Mode themes.
So first, I changed the ListView and associated Header with:
SetWindowTheme(hwndListView, isDarkModeEnabled() ? L"Explorer" : nullptr, nullptr);
SetWindowTheme(hwndListViewHeader, isDarkModeEnabled() ? L"ItemsView" : nullptr, nullptr);
I can set the ListView background color to any custom color I choose, while answering to the WM_THEMECHANGED message and doing a ListView_SetBkColor() macro.
Unfortunately, it seems I can't do it with the associated Header Control, I must resort to Custom Draw. So I did. I subclassed the ListView, because this is the window handle that will receive WM_NOTIFY messages from the Header control, and when responding to NM_CUSTOMDRAW message, my code looks like this:
case WM_NOTIFY:
{
LPNMHDR nmhdr = reinterpret_cast<LPNMHDR>(lParam);
if (nmhdr->code == NM_CUSTOMDRAW)
{
LPNMCUSTOMDRAW lpcd = reinterpret_cast<LPNMCUSTOMDRAW>(lParam);
switch (lpcd->dwDrawStage)
{
case CDDS_PREPAINT:
{
if (!PluginDarkMode::isEnabled())
return CDRF_DODEFAULT;
FillRect(lpcd->hdc, &lpcd->rc, getDarkerBackgroundBrush());
return CDRF_NOTIFYITEMDRAW | CDRF_NOTIFYPOSTPAINT;
}
case CDDS_ITEMPREPAINT:
{
return DrawListViewHeaderItem(lParam); // This function draws the item entirely and then returns CDRF_SKIPDEFAULT.
}
case CDDS_POSTPAINT:
// Calculates the undrawn border outside columns
HWND hHeader = lpcd->hdr.hwndFrom;
int count = static_cast<int>(Header_GetItemCount(hHeader));
int colsWidth = 0;
RECT wRc = {};
for (int i = 0; i < count; i++)
{
Header_GetItemRect(hHeader, i, &wRc);
colsWidth += wRc.right - wRc.left;
}
RECT clientRect;
GetClientRect(hHeader, &clientRect);
if (clientRect.right > (colsWidth + 1))
{
clientRect.left = colsWidth + 1;
HDC hdc = GetDC(hHeader);
FillRect(hdc, &clientRect, getDarkerBackgroundBrush());
ReleaseDC(hHeader, hdc);
}
return CDRF_SKIPDEFAULT;
}
}
break;
}
Now, my problem is that, although this seems fine, my control will always end up with a black rectangle outside the column's area (the empty space where no column exists). And this effect persists up until I move the mouse outside the header control area.
For example:
And when the mouse leaves the area:
Any ideas of how to solve this?
After asking this question, I changed my code. It works, but when WM_PAINT paints the window and the cursor is moving in it, the painting is not done at the same time everywhere. Here you have a video to see it better. This is my WM_PAINT:
//TV is a struct with the dimensions of the window.
//BitmapBuffer is the bitmap containing the painting.
static int cont;
cont++;
HDC HDc;
PAINTSTRUCT ps;
HDc = BeginPaint(identifier, &ps);
Gdiplus::Graphics lienzo (HDc);
AlphaBlend(HDc, 0, 0, TV.width+4, TV.height+4, buffer, 0, 0, TV.width+4, TV.height+4, CopyInfo);
EndPaint(identifier, &ps);
Since the problem is when moving the mouse, maybe the WM_NCHITTEST message has something to do with it:
case WM_NCHITTEST:
POINTS point1 = MAKEPOINTS(lParam);
POINT point2;
point2.x = point1.x;
point2.y = point1.y;
ScreenToClient(hwnd, &point2);
if (PtInRegion(region, point2.x, point2.y))
{
if (inWindow == false) //inWindow is true when the cursor is in the window
{
inWindow = true;
TrackMouseEvent(&structure);
Repaint(); //this function repaint the buffer and after call invalidrect
}
return HTCLIENT;
}
else
{
if (inWindow == true)
{
inWindow = false;
Repaint();
}
return HTTRANSPARENT;
}
break;
Does anyone have an idea why this happens?
It's hard to see the problem, because your code doesn't define Repaint. However, you should be using InvalidateRect to tell Windows which area is being updated.
THAT SAID...
Windows is hard to program for updating images with out using a double buffering technique. This is when you draw to a memory (bitmap) then bitblt the bitmap to the screen.
You find this answer useful Reduce flicker with GDI+ and C++
I am creating desktop application using C++ and pure WinApi. I need to display image that was given to me as SVG.
Since WinAPI supports only EMF files as vector format, I have used Inkscape to convert the file into EMF. My graphics design skills are at beginner level, but I have managed to convert SVG file into EMF successfully. However, the result is not looking as the original one, it is less "precise" so to say.
If I export the SVG as PNG and display it with GDI+, the result is the same as the original file. Unfortunately I need vector format.
To see exactly what I mean, download SVG, and EMF and PNG that I made here. Just click on Download:test.rar above 5 yellow stars ( see image below ).
Here are the instructions for creating minimal application that reproduces the problem:
1) Create default Win32 project in Visual Studio ( I use VS 2008, but this shouldn't be the problem );
2) Rewrite WM_PAINT like this:
case WM_PAINT:
{
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
RECT rcClient;
GetClientRect( hWnd, &rcClient );
FillRect( hdc, &rcClient, (HBRUSH)GetStockObject( LTGRAY_BRUSH) );
// put metafile in the same place your app is
HENHMETAFILE hemf = GetEnhMetaFile( L".\\test.emf" );
ENHMETAHEADER emh;
GetEnhMetaFileHeader( hemf, sizeof(emh), &emh );
// rescale metafile, and keep proportion
UINT o_height = emh.rclFrame.bottom - emh.rclFrame.top,
o_width = emh.rclFrame.right - emh.rclFrame.left;
float scale = 0.5;
scale = (float)( rcClient.right - rcClient.left ) / o_width;
if( (float)( rcClient.bottom - rcClient.top ) / o_height < scale )
scale = (float)( rcClient.bottom - rcClient.top ) / o_height;
int marginX = ( rcClient.right - rcClient.left ) - (int)( o_width * scale );
int marginY = ( rcClient.bottom - rcClient.top ) - (int)( o_height * scale );
marginX /= 2;
marginY /= 2;
rcClient.left = rcClient.left + marginX;
rcClient.right = rcClient.right - marginX;
rcClient.top = rcClient.top + marginY;
rcClient.bottom = rcClient.bottom - marginY;
// Draw the picture.
PlayEnhMetaFile( hdc, hemf, &rcClient );
// Release the metafile handle.
DeleteEnhMetaFile(hemf);
EndPaint(hWnd, &ps);
}
break;
3) Add following handlers for WM_SIZE and WM_ERASEBKGND just below WM_PAINT :
case WM_SIZE:
InvalidateRect( hWnd, NULL, FALSE );
return 0L;
case WM_ERASEBKGND:
return 1L;
4) Resize the window to the smallest possible size, and then maximize it.
Notice that the bigger the window gets, the better the image quality is, but the smaller it gets the "less precise" the image gets. I tested this on Windows XP.
I am asking your help to get the same graphic quality of the EMF file as the original SVG.
Thank you for your time and efforts. Best regards.
Solved it!
The solution makes much, if not all of the solution I've submitted redundant. I've therefore decided to replace it with this one.
There's a number of things to take into account and a number of concepts that are employed to get the desired result. These include (in no particular order)
The need to set a maskColour that closely matches the background, while also not being present in the final computed image. Pixels that straddle the border between transparent/opaque areas are blended values of the mask and the EMF's colour at that point.
The need to choose a scaling rate that's appropriate for the source image - in the case of this image and the code I've used, I chose 8. This means that we're drawing this particular EMF at about a megapixel, even though the destination is likely to be in the vicinity of about 85k pixels.
The need to manually set the alpha channel of the generated 32bit HBITMAP, since the GDI stretching/drawing functions disregard this channel, yet the AlphaBlend function requires them to be accurate.
I also note that I've used old code to draw the background manually each time the screen is refreshed. A much better approach would be to create a patternBrush once which is then simply copied using the FillRect function. This is much faster than filling the rect with a solid colour and then drawing the lines over the top. I can't be bothered to re-write that part of the code, though I'll include a snippet for reference that I've used in other projects in the past.
Here's a couple of shots of the result I get from the code below:
Here's the code I used to achieve it:
#define WINVER 0x0500 // for alphablend stuff
#include <windows.h>
#include <commctrl.h>
#include <stdio.h>
#include <stdint.h>
#include "resource.h"
HINSTANCE hInst;
HBITMAP mCreateDibSection(HDC hdc, int width, int height, int bitCount)
{
BITMAPINFO bi;
ZeroMemory(&bi, sizeof(bi));
bi.bmiHeader.biSize = sizeof(bi.bmiHeader);
bi.bmiHeader.biWidth = width;
bi.bmiHeader.biHeight = height;
bi.bmiHeader.biPlanes = 1;
bi.bmiHeader.biBitCount = bitCount;
bi.bmiHeader.biCompression = BI_RGB;
return CreateDIBSection(hdc, &bi, DIB_RGB_COLORS, 0,0,0);
}
void makePixelsTransparent(HBITMAP bmp, byte r, byte g, byte b)
{
BITMAP bm;
GetObject(bmp, sizeof(bm), &bm);
int x, y;
for (y=0; y<bm.bmHeight; y++)
{
uint8_t *curRow = (uint8_t *)bm.bmBits;
curRow += y * bm.bmWidthBytes;
for (x=0; x<bm.bmWidth; x++)
{
if ((curRow[x*4 + 0] == b) && (curRow[x*4 + 1] == g) && (curRow[x*4 + 2] == r))
{
curRow[x*4 + 0] = 0; // blue
curRow[x*4 + 1] = 0; // green
curRow[x*4 + 2] = 0; // red
curRow[x*4 + 3] = 0; // alpha
}
else
curRow[x*4 + 3] = 255; // alpha
}
}
}
// Note: maskCol should be as close to the colour of the background as is practical
// this is because the pixels that border transparent/opaque areas will have
// their colours derived from a blending of the image colour and the maskColour
//
// I.e - if drawing to a white background (255,255,255), you should NOT use a mask of magenta (255,0,255)
// this would result in a magenta-ish border
HBITMAP HbitmapFromEmf(HENHMETAFILE hEmf, int width, int height, COLORREF maskCol)
{
ENHMETAHEADER emh;
GetEnhMetaFileHeader(hEmf, sizeof(emh), &emh);
int emfWidth, emfHeight;
emfWidth = emh.rclFrame.right - emh.rclFrame.left;
emfHeight = emh.rclFrame.bottom - emh.rclFrame.top;
// these are arbitrary and selected to give a good mix of speed and accuracy
// it may be worth considering passing this value in as a parameter to allow
// fine-tuning
emfWidth /= 8;
emfHeight /= 8;
// draw at 'native' size
HBITMAP emfSrcBmp = mCreateDibSection(NULL, emfWidth, emfHeight, 32);
HDC srcDC = CreateCompatibleDC(NULL);
HBITMAP oldSrcBmp = (HBITMAP)SelectObject(srcDC, emfSrcBmp);
RECT tmpEmfRect, emfRect;
SetRect(&tmpEmfRect, 0,0,emfWidth,emfHeight);
// fill background with mask colour
HBRUSH bkgBrush = CreateSolidBrush(maskCol);
FillRect(srcDC, &tmpEmfRect, bkgBrush);
DeleteObject(bkgBrush);
// draw emf
PlayEnhMetaFile(srcDC, hEmf, &tmpEmfRect);
HDC dstDC = CreateCompatibleDC(NULL);
HBITMAP oldDstBmp;
HBITMAP result;
result = mCreateDibSection(NULL, width, height, 32);
oldDstBmp = (HBITMAP)SelectObject(dstDC, result);
SetStretchBltMode(dstDC, HALFTONE);
StretchBlt(dstDC, 0,0,width,height, srcDC, 0,0, emfWidth,emfHeight, SRCCOPY);
SelectObject(srcDC, oldSrcBmp);
DeleteDC(srcDC);
DeleteObject(emfSrcBmp);
SelectObject(dstDC, oldDstBmp);
DeleteDC(dstDC);
makePixelsTransparent(result, GetRValue(maskCol),GetGValue(maskCol),GetBValue(maskCol));
return result;
}
int rectWidth(RECT &r)
{
return r.right - r.left;
}
int rectHeight(RECT &r)
{
return r.bottom - r.top;
}
void onPaintEmf(HWND hwnd, HENHMETAFILE srcEmf)
{
PAINTSTRUCT ps;
RECT mRect, drawRect;
HDC hdc;
double scaleWidth, scaleHeight, scale;
int spareWidth, spareHeight;
int emfWidth, emfHeight;
ENHMETAHEADER emh;
GetClientRect( hwnd, &mRect );
hdc = BeginPaint(hwnd, &ps);
// calculate the draw-size - retain aspect-ratio.
GetEnhMetaFileHeader(srcEmf, sizeof(emh), &emh );
emfWidth = emh.rclFrame.right - emh.rclFrame.left;
emfHeight = emh.rclFrame.bottom - emh.rclFrame.top;
scaleWidth = (double)rectWidth(mRect) / emfWidth;
scaleHeight = (double)rectHeight(mRect) / emfHeight;
scale = min(scaleWidth, scaleHeight);
int drawWidth, drawHeight;
drawWidth = emfWidth * scale;
drawHeight = emfHeight * scale;
spareWidth = rectWidth(mRect) - drawWidth;
spareHeight = rectHeight(mRect) - drawHeight;
drawRect = mRect;
InflateRect(&drawRect, -spareWidth/2, -spareHeight/2);
// create a HBITMAP from the emf and draw it
// **** note that the maskCol matches the background drawn by the below function ****
HBITMAP srcImg = HbitmapFromEmf(srcEmf, drawWidth, drawHeight, RGB(230,230,230) );
HDC memDC;
HBITMAP old;
memDC = CreateCompatibleDC(hdc);
old = (HBITMAP)SelectObject(memDC, srcImg);
byte alpha = 255;
BLENDFUNCTION bf = {AC_SRC_OVER,0,alpha,AC_SRC_ALPHA};
AlphaBlend(hdc, drawRect.left,drawRect.top, drawWidth,drawHeight,
memDC, 0,0,drawWidth,drawHeight, bf);
SelectObject(memDC, old);
DeleteDC(memDC);
DeleteObject(srcImg);
EndPaint(hwnd, &ps);
}
void drawHeader(HDC dst, RECT headerRect)
{
HBRUSH b1;
int i,j;//,headerHeight = (headerRect.bottom - headerRect.top)+1;
b1 = CreateSolidBrush(RGB(230,230,230));
FillRect(dst, &headerRect,b1);
DeleteObject(b1);
HPEN oldPen, curPen;
curPen = CreatePen(PS_SOLID, 1, RGB(216,216,216));
oldPen = (HPEN)SelectObject(dst, curPen);
for (j=headerRect.top;j<headerRect.bottom;j+=10)
{
MoveToEx(dst, headerRect.left, j, NULL);
LineTo(dst, headerRect.right, j);
}
for (i=headerRect.left;i<headerRect.right;i+=10)
{
MoveToEx(dst, i, headerRect.top, NULL);
LineTo(dst, i, headerRect.bottom);
}
SelectObject(dst, oldPen);
DeleteObject(curPen);
MoveToEx(dst, headerRect.left,headerRect.bottom,NULL);
LineTo(dst, headerRect.right,headerRect.bottom);
}
BOOL CALLBACK DlgMain(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
static HENHMETAFILE hemf;
switch(uMsg)
{
case WM_INITDIALOG:
{
hemf = GetEnhMetaFile( "test.emf" );
}
return TRUE;
case WM_PAINT:
onPaintEmf(hwndDlg, hemf);
return 0;
case WM_ERASEBKGND:
{
RECT mRect;
GetClientRect(hwndDlg, &mRect);
drawHeader( (HDC)wParam, mRect);
}
return true;
case WM_SIZE:
InvalidateRect( hwndDlg, NULL, true );
return 0L;
case WM_CLOSE:
{
EndDialog(hwndDlg, 0);
}
return TRUE;
case WM_COMMAND:
{
switch(LOWORD(wParam))
{
}
}
return TRUE;
}
return FALSE;
}
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
hInst=hInstance;
InitCommonControls();
return DialogBox(hInst, MAKEINTRESOURCE(DLG_MAIN), NULL, (DLGPROC)DlgMain);
}
Finally, here's an example of creating a patternBrush for filling the background using the FillRect function. This approach is suitable for any tileable background.
HBRUSH makeCheckerBrush(int squareSize, COLORREF col1, COLORREF col2)
{
HDC memDC, tmpDC = GetDC(NULL);
HBRUSH result, br1, br2;
HBITMAP old, bmp;
RECT rc, r1, r2;
br1 = CreateSolidBrush(col1);
br2 = CreateSolidBrush(col2);
memDC = CreateCompatibleDC(tmpDC);
bmp = CreateCompatibleBitmap(tmpDC, 2*squareSize, 2*squareSize);
old = (HBITMAP)SelectObject(memDC, bmp);
SetRect(&rc, 0,0, squareSize*2, squareSize*2);
FillRect(memDC, &rc, br1);
// top right
SetRect(&r1, squareSize, 0, 2*squareSize, squareSize);
FillRect(memDC, &r1, br2);
// bot left
SetRect(&r2, 0, squareSize, squareSize, 2*squareSize);
FillRect(memDC, &r2, br2);
SelectObject(memDC, old);
DeleteObject(br1);
DeleteObject(br2);
ReleaseDC(0, tmpDC);
DeleteDC(memDC);
result = CreatePatternBrush(bmp);
DeleteObject(bmp);
return result;
}
Example of result, created with:
HBRUSH bkBrush = makeCheckerBrush(8, RGB(153,153,153), RGB(102,102,102));
I am trying to make a radio button control with a transparent background using only Win32 when themes are enabled. The reason for doing this is to allow a radio button to be placed over an image and have the image show (rather than the grey default control background).
What happens out of the box is that the control will have the grey default control background and the standard method of changing this by handling either WM_CTLCOLORSTATIC or WM_CTLCOLORBTN as shown below does not work:
case WM_CTLCOLORSTATIC:
hdcStatic = (HDC)wParam;
SetTextColor(hdcStatic, RGB(0,0,0));
SetBkMode(hdcStatic,TRANSPARENT);
return (LRESULT)GetStockObject(NULL_BRUSH);
break;
My research so far indicates that Owner Draw is the only way to achieve this. I've managed to get most of the way with an Owner Draw radio button - with the code below I have a radio button and a transparent background (the background is set in WM_CTLCOLORBTN). However, the edges of the radio check are cut off using this method - I can get them back by uncommenting the call to the function DrawThemeParentBackgroundEx but this breaks the transparency.
void DrawRadioControl(HWND hwnd, HTHEME hTheme, HDC dc, bool checked, RECT rcItem)
{
if (hTheme)
{
static const int cb_size = 13;
RECT bgRect, textRect;
HFONT font = (HFONT)SendMessageW(hwnd, WM_GETFONT, 0, 0);
WCHAR *text = L"Experiment";
DWORD state = ((checked) ? RBS_CHECKEDNORMAL : RBS_UNCHECKEDNORMAL) | ((bMouseOverButton) ? RBS_HOT : 0);
GetClientRect(hwnd, &bgRect);
GetThemeBackgroundContentRect(hTheme, dc, BP_RADIOBUTTON, state, &bgRect, &textRect);
DWORD dtFlags = DT_VCENTER | DT_SINGLELINE;
if (dtFlags & DT_SINGLELINE) /* Center the checkbox / radio button to the text. */
bgRect.top = bgRect.top + (textRect.bottom - textRect.top - cb_size) / 2;
/* adjust for the check/radio marker */
bgRect.bottom = bgRect.top + cb_size;
bgRect.right = bgRect.left + cb_size;
textRect.left = bgRect.right + 6;
//Uncommenting this line will fix the button corners but breaks transparency
//DrawThemeParentBackgroundEx(hwnd, dc, DTPB_USECTLCOLORSTATIC, NULL);
DrawThemeBackground(hTheme, dc, BP_RADIOBUTTON, state, &bgRect, NULL);
if (text)
{
DrawThemeText(hTheme, dc, BP_RADIOBUTTON, state, text, lstrlenW(text), dtFlags, 0, &textRect);
}
}
else
{
// Code for rendering the radio when themes are not present
}
}
The method above is called from WM_DRAWITEM as shown below:
case WM_DRAWITEM:
{
LPDRAWITEMSTRUCT pDIS = (LPDRAWITEMSTRUCT)lParam;
hTheme = OpenThemeData(hDlg, L"BUTTON");
HDC dc = pDIS->hDC;
wchar_t sCaption[100];
GetWindowText(GetDlgItem(hDlg, pDIS->CtlID), sCaption, 100);
std::wstring staticText(sCaption);
DrawRadioControl(pDIS->hwndItem, hTheme, dc, radio_group.IsButtonChecked(pDIS->CtlID), pDIS->rcItem, staticText);
SetBkMode(dc, TRANSPARENT);
SetTextColor(hdcStatic, RGB(0,0,0));
return TRUE;
}
So my question is two parts I suppose:
Have I missed some other way to achieve my desired result?
Is it possible to fix the clipped button corners issue with my code and still have a transparent background
After looking at this on and off for nearly three months I've finally found a solution that I'm pleased with. What I eventually found was that the radio button edges were for some reason not being drawn by the routine within WM_DRAWITEM but that if I invalidated the radio button control's parent in a rectangle around the control, they appeared.
Since I could not find a single good example of this I'm providing the full code (in my own solution I have encapsulated my owner drawn controls into their own class, so you will need to provide some details such as whether the button is checked or not)
This is the creation of the radiobutton (adding it to the parent window) also setting GWL_UserData and subclassing the radiobutton:
HWND hWndControl = CreateWindow( _T("BUTTON"), caption, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW,
xPos, yPos, width, height, parentHwnd, (HMENU) id, NULL, NULL);
// Using SetWindowLong and GWL_USERDATA I pass in the this reference, allowing my
// window proc toknow about the control state such as if it is selected
SetWindowLong( hWndControl, GWL_USERDATA, (LONG)this);
// And subclass the control - the WndProc is shown later
SetWindowSubclass(hWndControl, OwnerDrawControl::WndProc, 0, 0);
Since it is owner draw we need to handle the WM_DRAWITEM message in the parent window proc.
case WM_DRAWITEM:
{
LPDRAWITEMSTRUCT pDIS = (LPDRAWITEMSTRUCT)lParam;
hTheme = OpenThemeData(hDlg, L"BUTTON");
HDC dc = pDIS->hDC;
wchar_t sCaption[100];
GetWindowText(GetDlgItem(hDlg, pDIS->CtlID), sCaption, 100);
std::wstring staticText(sCaption);
// Controller here passes to a class that holds a map of all controls
// which then passes on to the correct instance of my owner draw class
// which has the drawing code I show below
controller->DrawControl(pDIS->hwndItem, hTheme, dc, pDIS->rcItem,
staticText, pDIS->CtlID, pDIS->itemState, pDIS->itemAction);
SetBkMode(dc, TRANSPARENT);
SetTextColor(hdcStatic, RGB(0,0,0));
CloseThemeData(hTheme);
return TRUE;
}
Here is the DrawControl method - it has access to class level variables to allow state to be managed since with owner draw this is not handled automatically.
void OwnerDrawControl::DrawControl(HWND hwnd, HTHEME hTheme, HDC dc, bool checked, RECT rcItem, std::wstring caption, int ctrlId, UINT item_state, UINT item_action)
{
// Check if we need to draw themed data
if (hTheme)
{
HWND parent = GetParent(hwnd);
static const int cb_size = 13;
RECT bgRect, textRect;
HFONT font = (HFONT)SendMessageW(hwnd, WM_GETFONT, 0, 0);
DWORD state;
// This method handles both radio buttons and checkboxes - the enums here
// are part of my own code, not Windows enums.
// We also have hot tracking - this is shown in the window subclass later
if (Type() == RADIO_BUTTON)
state = ((checked) ? RBS_CHECKEDNORMAL : RBS_UNCHECKEDNORMAL) | ((is_hot_) ? RBS_HOT : 0);
else if (Type() == CHECK_BOX)
state = ((checked) ? CBS_CHECKEDNORMAL : CBS_UNCHECKEDNORMAL) | ((is_hot_) ? RBS_HOT : 0);
GetClientRect(hwnd, &bgRect);
// the theme type is either BP_RADIOBUTTON or BP_CHECKBOX where these are Windows enums
DWORD theme_type = ThemeType();
GetThemeBackgroundContentRect(hTheme, dc, theme_type, state, &bgRect, &textRect);
DWORD dtFlags = DT_VCENTER | DT_SINGLELINE;
if (dtFlags & DT_SINGLELINE) /* Center the checkbox / radio button to the text. */
bgRect.top = bgRect.top + (textRect.bottom - textRect.top - cb_size) / 2;
/* adjust for the check/radio marker */
// The +3 and +6 are a slight fudge to allow the focus rectangle to show correctly
bgRect.bottom = bgRect.top + cb_size;
bgRect.left += 3;
bgRect.right = bgRect.left + cb_size;
textRect.left = bgRect.right + 6;
DrawThemeBackground(hTheme, dc, theme_type, state, &bgRect, NULL);
DrawThemeText(hTheme, dc, theme_type, state, caption.c_str(), lstrlenW(caption.c_str()), dtFlags, 0, &textRect);
// Draw Focus Rectangle - I still don't really like this, it draw on the parent
// mainly to work around the way DrawFocus toggles the focus rect on and off.
// That coupled with some of my other drawing meant this was the only way I found
// to get a reliable focus effect.
BOOL bODAEntire = (item_action & ODA_DRAWENTIRE);
BOOL bIsFocused = (item_state & ODS_FOCUS);
BOOL bDrawFocusRect = !(item_state & ODS_NOFOCUSRECT);
if (bIsFocused && bDrawFocusRect)
{
if ((!bODAEntire))
{
HDC pdc = GetDC(parent);
RECT prc = GetMappedRectanglePos(hwnd, parent);
DrawFocus(pdc, prc);
}
}
}
// This handles drawing when we don't have themes
else
{
TEXTMETRIC tm;
GetTextMetrics(dc, &tm);
RECT rect = { rcItem.left ,
rcItem.top ,
rcItem.left + tm.tmHeight - 1,
rcItem.top + tm.tmHeight - 1};
DWORD state = ((checked) ? DFCS_CHECKED : 0 );
if (Type() == RADIO_BUTTON)
DrawFrameControl(dc, &rect, DFC_BUTTON, DFCS_BUTTONRADIO | state);
else if (Type() == CHECK_BOX)
DrawFrameControl(dc, &rect, DFC_BUTTON, DFCS_BUTTONCHECK | state);
RECT textRect = rcItem;
textRect.left = rcItem.left + 19;
SetTextColor(dc, ::GetSysColor(COLOR_BTNTEXT));
SetBkColor(dc, ::GetSysColor(COLOR_BTNFACE));
DrawText(dc, caption.c_str(), -1, &textRect, DT_WORDBREAK | DT_TOP);
}
}
Next is the window proc that is used to subclass the radio button control - this
is called with all windows messages and handles several before then passing unhandled
ones on to the default proc.
LRESULT OwnerDrawControl::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam,
LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
// Get the button parent window
HWND parent = GetParent(hWnd);
// The page controller and the OwnerDrawControl hold some information we need to draw
// correctly, such as if the control is already set hot.
st_mini::IPageController * controller = GetWinLong<st_mini::IPageController *> (parent);
// Get the control
OwnerDrawControl *ctrl = (OwnerDrawControl*)GetWindowLong(hWnd, GWL_USERDATA);
switch (uMsg)
{
case WM_LBUTTONDOWN:
if (controller)
{
int ctrlId = GetDlgCtrlID(hWnd);
// OnCommand is where the logic for things like selecting a radiobutton
// and deselecting the rest of the group lives.
// We also call our Invalidate method there, which redraws the radio when
// it is selected. The Invalidate method will be shown last.
controller->OnCommand(parent, ctrlId, 0);
return (0);
}
break;
case WM_LBUTTONDBLCLK:
// We just treat doubleclicks as clicks
PostMessage(hWnd, WM_LBUTTONDOWN, wParam, lParam);
break;
case WM_MOUSEMOVE:
{
if (controller)
{
// This is our hot tracking allowing us to paint the control
// correctly when the mouse is over it - it sets flags that get
// used by the above DrawControl method
if(!ctrl->IsHot())
{
ctrl->SetHot(true);
// We invalidate to repaint
ctrl->InvalidateControl();
// Track the mouse event - without this the mouse leave message is not sent
TRACKMOUSEEVENT tme;
tme.cbSize = sizeof(TRACKMOUSEEVENT);
tme.dwFlags = TME_LEAVE;
tme.hwndTrack = hWnd;
TrackMouseEvent(&tme);
}
}
return (0);
}
break;
case WM_MOUSELEAVE:
{
if (controller)
{
// Turn off the hot display on the radio
if(ctrl->IsHot())
{
ctrl->SetHot(false);
ctrl->InvalidateControl();
}
}
return (0);
}
case WM_SETFOCUS:
{
ctrl->InvalidateControl();
}
case WM_KILLFOCUS:
{
RECT rcItem;
GetClientRect(hWnd, &rcItem);
HDC dc = GetDC(parent);
RECT prc = GetMappedRectanglePos(hWnd, parent);
DrawFocus(dc, prc);
return (0);
}
case WM_ERASEBKGND:
return 1;
}
// Any messages we don't process must be passed onto the original window function
return DefSubclassProc(hWnd, uMsg, wParam, lParam);
}
Finally the last little piece of the puzzle is that you need to invalidate the control (redraw it) at the right times. I eventually found that invalidating the parent allowed the drawing to work 100% correctly. This was causing flicker until I realised that I could get away by only invalidating a rectangle as big as the radio check, rather than as big as the whole control including text as I had been.
void InvalidateControl()
{
// GetMappedRectanglePos is my own helper that uses MapWindowPoints
// to take a child control and map it to its parent
RECT rc = GetMappedRectanglePos(ctrl_, parent_);
// This was my first go, that caused flicker
// InvalidateRect(parent_, &rc_, FALSE);
// Now I invalidate a smaller rectangle
rc.right = rc.left + 13;
InvalidateRect(parent_, &rc, FALSE);
}
A lot of code and effort for something that should be simple - drawing a themed radio button over a background image. Hopefully the answer will save someone else some pain!
* One big caveat with this is it only works 100% correctly for owner controls that are over a background (such as a fill rectangle or an image). That is ok though, since it is only needed when drawing the radio control over a background.
I've done this some time ago as well. I remember the key was to just create the (radio) buttons as usual. The parent must be the dialog or window, not a tab control. You could do it differently but I created a memory dc (m_mdc) for the dialog and painted the background on that. Then add the OnCtlColorStatic and OnCtlColorBtn for your dialog:
virtual HBRUSH OnCtlColorStatic(HDC hDC, HWND hWnd)
{
RECT rc;
GetRelativeClientRect(hWnd, m_hWnd, &rc);
BitBlt(hDC, 0, 0, rc.right - rc.left, rc.bottom - rc.top, m_mdc, rc.left, rc.top, SRCCOPY);
SetBkColor(hDC, GetSysColor(COLOR_BTNFACE));
if (IsAppThemed())
SetBkMode(hDC, TRANSPARENT);
return (HBRUSH)GetStockObject(NULL_BRUSH);
}
virtual HBRUSH OnCtlColorBtn(HDC hDC, HWND hWnd)
{
return OnCtlColorStatic(hDC, hWnd);
}
The code uses some in-house classes and functions similar to MFC, but I think you should get the idea. As you can see it draws the background of these controls from the memory dc, that's key.
Give this a try and see if it works!
EDIT: If you add a tab control to the dialog and put the controls on the tab (that was the case in my app) you must capture it's background and copy it to the memory dc of the dialog. It's a bit of an ugly hack but it works, even if the machine is running some extravagant theme that uses a gradient tab background:
// calculate tab dispay area
RECT rc;
GetClientRect(m_tabControl, &rc);
m_tabControl.AdjustRect(false, &rc);
RECT rc2;
GetRelativeClientRect(m_tabControl, m_hWnd, &rc2);
rc.left += rc2.left;
rc.right += rc2.left;
rc.top += rc2.top;
rc.bottom += rc2.top;
// copy that area to background
HRGN hRgn = CreateRectRgnIndirect(&rc);
GetRelativeClientRect(m_hWnd, m_tabControl, &rc);
SetWindowOrgEx(m_mdc, rc.left, rc.top, NULL);
SelectClipRgn(m_mdc, hRgn);
SendMessage(m_tabControl, WM_PRINTCLIENT, (WPARAM)(HDC)m_mdc, PRF_CLIENT);
SelectClipRgn(m_mdc, NULL);
SetWindowOrgEx(m_mdc, 0, 0, NULL);
DeleteObject(hRgn);
Another interesting point, while we're busy now, to get it all non-flickering create the parent and children (buttons, statics, tabs etc) with the WS_CLIPCHILDREN and WS_CLIPSIBLINGS style. The the order of creation is essential: First create the controls you put on the tabs, then create the tab control. Not the other way around (although it feels more intuitive). That because the tab control should clip the area obscured by the controls on it :)
I can't immediately try this out, but so far as I recall, you don't need owner draw. You need to do this:
Return 1 from WM_ERASEBKGND.
Call DrawThemeParentBackground from WM_CTLCOLORSTATIC to draw the background there.
Return GetStockObject(NULL_BRUSH) from WM_CTLCOLORSTATIC.
Knowing the sizes and coordinates radio button, we will copy the
image to them closed.
Then we create a brush by means of
BS_PATTERN style CreateBrushIndirect
Farther according to the
usual scheme - we return handle to this brush in reply to COLOR -
the message (WM_CTLCOLORSTATIC).
I have no idea why you are doing it so difficult, this is best solved via CustomDrawing
This is my MFC Handler to draw a Notebook on a CTabCtrl control. I'm not really sure why i need to Inflate the Rectangle, because if i don't do it a black border is drawn.
And another conceptional bug MS made is IMHO that i have to overwrite the PreErase drawing phase instead of the PostErase. But if i do the later the checkbox is gone.
afx_msg void AguiRadioButton::OnCustomDraw(NMHDR* notify, LRESULT* res) {
NMCUSTOMDRAW* cd = (NMCUSTOMDRAW*)notify;
if (cd->dwDrawStage == CDDS_PREERASE) {
HTHEME theme = OpenThemeData(m_hWnd, L"Button");
CRect r = cd->rc; r.InflateRect(1,1,1,1);
DrawThemeBackground(theme, cd->hdc, TABP_BODY, 0, &r,NULL);
CloseThemeData(theme);
*res = 0;
}
*res = 0;
}
Ok so I'm working with vectors today yaya!
well im also working with getcursorpos() and i get weird results.
here is the code:
VOID fRegularShot(HDC hdc, HWND hWnd)
{
Graphics graphics(hdc);
Image shot(L"RegularShots.png");
long index=0;
while(index<=(long)pRegularShots.size())
{
index+=2;
int x=pRegularShots.at(index);
int y1=index+1;
int y=pRegularShots.at(y1);
graphics.DrawImage(&shot, x, y);
}
}
///////////////////////////////////////////////////
event
case WM_LBUTTONDOWN:
iRegularShots=0;
POINT pt;
GetCursorPos(&pt);
pRegularShots.insert(pRegularShots.begin()+1, pt.y);
pRegularShots.insert(pRegularShots.begin()+1, pt.x);
InvalidateRect(hWnd, rect, false);
break;
Well basically function fregularshots() get called and use the vector elements which contains the positions of the cursor than draws the image on the cursor positions.
but it doesn't seem to draw it on the cursor positions.
any ideas?
GetCursorPos returns cursor position in screen coordinates. Use ScreenToClient(hWnd, ...) to convert it to window client coordinates.
GetCursorPos(&pt);
ScreenToClient(hWnd, &pt);
You can work also without GetCursorPos function. When WM_LBUTTONDOWN notification is received, lParam contains window client mouse coordinates: x in low-order word, y in high-order word:
xPos = GET_X_LPARAM(lParam);
yPos = GET_Y_LPARAM(lParam);
Edit:
Let's make this code more simple.
vector<POINT> pRegularShots;
VOID fRegularShot(HDC hdc, HWND hWnd)
{
Graphics graphics(hdc);
Image shot(L"RegularShots.png");
long index=0;
while(index < (long)pRegularShots.size())
{
graphics.DrawImage(&shot, pRegularShots[index].x, pRegularShots[index].y);
++index;
}
}
case WM_LBUTTONDOWN:
POINT pt;
pt.x = GET_X_LPARAM(lParam);
pt.y = GET_Y_LPARAM(lParam);
pRegularShots.push_back(pt);
InvalidateRect(hWnd, rect, false);
break;