#2382 Reverse arrow cursor is too small when GDI scaling is active

[Markus Nißl]

The reverse arrow cursor is too small when GDI scaling is active.

Merge request 37 addresses this issue.

[Markus Nißl]

Explanation of the patch:

While GDI scaling works with the first integral multiple of the device scale factor, the cursor has to be requested with the correct scale factor (i.e. with 1.5 instead of 2 in case of 150 % scaling). In commit [85fe64] the device scale factor of ScintillaWin is stored as a float instead of an int. Existing references then use GetFirstIntegralMultipleDeviceScaleFactor() instead.

In commit [d5cdd6] reversArrowCursor.Load() is passed the correct dpi (dpi * deviceScaleFactor, ScintillaWin.cxx, line 735 ).

In PlatWin.cxx, LoadReversArrowCursor() now first features a local helper class CursorHelper which performs RAII and incorporates existing code to flip the bitmap.

The remainder of the function has the following changes:

1. Instead of using LoadCursor() that accepts no size, the cursor is loaded via LoadImage() and the desired width and height.
2. For step 1 to work correctly, the DPI awareness of the thread has to be changed to DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2.
3. If the returned cursor does not match the requested width and height, the cursor is copied as before.
4. If a bitmap could be retrieved, the new cursor is created from the flipped bitmap (reverseArrowCursor = cursorHelper.CreateFlippedCursor()).
5. The DPI awareness of the thread is reset to its original value.

[Neil Hodgson]

Committed as [7267f2].

[Neil Hodgson]

Committed as [7267f2].