Classes
struct	BlitOpts
	Options for drawBitmapMasked. Zero-init = plain transparent blit. More...

Enumerations
enum class	DisplayTarget : uint8_t { Cp437 = 0 , Latin1 = 1 }
	Display encoding targets for decodeWebText(). More...

Functions
void	drawHeaderLeft (Gdey029T94 gfx, const char title, int x, int y, uint16_t width, int underlineOffset=18)
void	drawHeaderCentered (Gdey029T94 gfx, const char title, int y, uint16_t width)
	Draws a centered header title.
void	drawFooterBar (Gdey029T94 gfx, uint16_t width, uint16_t height, const char prefix, const char *hint, bool force)
	Draws footer bar with optional prefix and hint text.
void	drawScrollIndicator (Gdey029T94 *gfx, int x, int y, int listHeight, uint16_t totalItems, uint16_t visibleItems, uint16_t scrollPos)
	Draws scroll arrows and scrollbar thumb.
void	drawDialogFrame (Gdey029T94 *gfx, int x, int y, int w, int h)
	Draws a framed dialog box with double border.
void	printTruncated (Adafruit_GFX gfx, const char text, int maxWidthPx)
	Print text at the current cursor, truncated with an ellipsis to fit maxWidthPx. Caller must have already called setCursor and setTextColor/setTextSize. Adafruit-GFX text wrap should be off.
uint8_t	cp437ToLatin1 (uint8_t c)
	Maps a CP437 byte to the equivalent Latin-1 byte for use with Unicode/Latin-1 indexed GFX fonts (e.g. FreeMonoBold*pt8b).
void	utf8ToCp437Inplace (char *buf)
	Decodes a UTF-8 string in place to CP437 single bytes. Truncates if the buffer is too small. Unmapped codepoints are dropped silently.
void	decodeWebText (const char in, char out, size_t out_size, DisplayTarget target=DisplayTarget::Cp437)
	Normalises a web payload for display: HTML named/numeric entities decode first, then UTF-8 multibyte sequences collapse into the single-byte layout expected by the target font.
void	drawCp437Text (Adafruit_GFX gfx, const char text)
	Prints a CP437 string by mapping each byte to Latin-1 before drawing. Use with TTF-derived GFX fonts (range 0x20..0xFF) that expect Latin-1 indices.
void	drawText (Adafruit_GFX gfx, const char text, const GFXfont *font)
	Draws CP437-encoded text correctly for the given font: the built-in glcdfont (font == nullptr) is CP437-indexed and receives the bytes raw; TTF-derived GFX fonts are Latin-1-indexed and receive a per-byte CP437->Latin1 mapping. This is the single point where the in-memory CP437 canonical form is adapted to the active font's index space. The caller must have set `font` on `gfx` and positioned the cursor.
void	printText (Adafruit_GFX gfx, const char text)
	Draws CP437 text with the built-in 6x8 glyph font, byte-for-byte.
void	measureText (Adafruit_GFX gfx, const char text, const GFXfont font, int16_t x0, int16_t y0, int16_t x1, int16_t y1, uint16_t w, uint16_t *h)
	Measures CP437 text exactly as drawText would render it with `font`, so width-based layout (centering, fitting, truncation) matches the drawn glyphs.
const GFXfont *	pickFontThatFits (Adafruit_GFX gfx, const char text, int maxWidthPx, const GFXfont const candidates, size_t count, bool cp437=false)
	Picks the largest font from `candidates` whose rendered width of `text` fits within `maxWidthPx`. Candidates are evaluated in array order; pass them sorted from largest to smallest so the first match is the biggest font that still fits.
void	measureCp437Text (Adafruit_GFX gfx, const char text, int16_t x0, int16_t y0, int16_t x1, int16_t y1, uint16_t w, uint16_t h)
	Measures a CP437 string using the current font (via Latin-1 mapping).
bool	ditherOn (int16_t x, int16_t y, uint8_t shade)
	True when the ordered-dither matrix inks pixel (x, y) for shade.
void	fillRectDither (Adafruit_GFX *gfx, int16_t x, int16_t y, int16_t w, int16_t h, uint8_t shade, uint16_t color)
	Fills a rectangle with an ordered-dither fake-grey pattern.
void	fillCircleDither (Adafruit_GFX *gfx, int16_t cx, int16_t cy, int16_t r, uint8_t shade, uint16_t color)
	Dithered filled circle; see fillRectDither.
void	fillTriangleDither (Adafruit_GFX *gfx, int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint8_t shade, uint16_t color)
	Dithered filled triangle; see fillRectDither.
void	drawBitmapMasked (Adafruit_GFX gfx, int16_t x, int16_t y, const uint8_t data, int16_t w, int16_t h, const BlitOpts &opts, uint16_t fg, uint16_t bg)
	Blit a packed 1-bpp bitmap with optional mask plane, flipping, 90-degree rotation, integer scaling and a horizontal source window.

Variables
constexpr int	FOOTER_HEIGHT = cdc::ui::layout::FOOTER_HEIGHT
constexpr int	SCROLL_INDICATOR_WIDTH = cdc::ui::layout::SCROLL_INDICATOR_WIDTH

Detailed Description

RenderHelpers

Shared rendering utilities for common UI chrome and dialogs.

Enumeration Type Documentation

◆ DisplayTarget

enum class cdc::ui::render::DisplayTarget : uint8_t

strong

Display encoding targets for decodeWebText().

Enumerator
Cp437	GFX builtin glcdfont (default after setFont(nullptr)).
Latin1	FreeMonoBold*pt8b fonts (Latin-1 indexed, 0x20..0xFF).

Definition at line 59 of file RenderHelpers.h.

Function Documentation

◆ cp437ToLatin1()

uint8_t cdc::ui::render::cp437ToLatin1 ( uint8_t c )

Maps a CP437 byte to the equivalent Latin-1 byte for use with Unicode/Latin-1 indexed GFX fonts (e.g. FreeMonoBold*pt8b).

Maps a CP437 byte to the equivalent Latin-1 byte for use with Latin-1 indexed GFX fonts (TTF-derived range 0x20..0xFF). ASCII (<0x80) and untracked codes pass through unchanged.

Parameters

c	CP437 byte value.

Returns: Latin-1 byte representing the same character, or c when no mapping is needed.

Definition at line 218 of file RenderHelpers.cpp.

Referenced by drawCp437Text(), and measureCp437Text().

◆ decodeWebText()

void cdc::ui::render::decodeWebText	(	const char *	in,
		char *	out,
		size_t	out_size,
		DisplayTarget	target = DisplayTarget::Cp437 )

Normalises a web payload for display: HTML named/numeric entities decode first, then UTF-8 multibyte sequences collapse into the single-byte layout expected by the target font.

target picks the output codepage:

DisplayTarget::Cp437 - matches the GFX builtin glcdfont.
DisplayTarget::Latin1 - matches the FreeMonoBold*pt8b fonts.

Output is always NUL-terminated. Unmapped codepoints are dropped. in and out must not alias.

Parameters

in	Source string (UTF-8, optionally containing HTML entities).
out	Destination buffer.
out_size	Capacity of out in bytes (including the terminator).
target	Encoding target. Defaults to CP437.

Definition at line 395 of file RenderHelpers.cpp.

References Latin1, and utf8ToCp437Inplace().

Referenced by host_str_to_display(), and cdc::plugin_manager::toDisplay().

◆ ditherOn()

bool cdc::ui::render::ditherOn	(	int16_t	x,
		int16_t	y,
		uint8_t	shade )

True when the ordered-dither matrix inks pixel (x, y) for shade.

Parameters

x	Pixel column.
y	Pixel row.
shade	Grey level 0 (white) .. 255 (black), quantised to 64 levels.

Definition at line 532 of file RenderHelpers.cpp.

Referenced by fillCircleDither(), fillRectDither(), and fillTriangleDither().

◆ drawBitmapMasked()

void cdc::ui::render::drawBitmapMasked	(	Adafruit_GFX *	gfx,
		int16_t	x,
		int16_t	y,
		const uint8_t *	data,
		int16_t	w,
		int16_t	h,
		const BlitOpts &	opts,
		uint16_t	fg,
		uint16_t	bg )

Blit a packed 1-bpp bitmap with optional mask plane, flipping, 90-degree rotation, integer scaling and a horizontal source window.

Rows are byte-padded, MSB first (the surface/QR/image convention). Without a mask, set bits paint fg and unset bits are transparent unless opts.opaque, in which case they paint bg. With a mask, only pixels whose mask bit is set are painted (data bit picks fg / bg), which allows drawing white pixels without making the whole rectangle opaque.

Definition at line 546 of file RenderHelpers.cpp.

References cdc::ui::render::BlitOpts::flipH, cdc::ui::render::BlitOpts::flipV, cdc::ui::render::BlitOpts::mask, cdc::ui::render::BlitOpts::opaque, cdc::ui::render::BlitOpts::rot90, cdc::ui::render::BlitOpts::scale, cdc::ui::scale, cdc::ui::render::BlitOpts::srcSpan, cdc::ui::render::BlitOpts::srcW, and cdc::ui::render::BlitOpts::srcX.

Referenced by host_surface_draw_sprite().

◆ drawCp437Text()

void cdc::ui::render::drawCp437Text	(	Adafruit_GFX *	gfx,
		const char *	text )

Prints a CP437 string by mapping each byte to Latin-1 before drawing. Use with TTF-derived GFX fonts (range 0x20..0xFF) that expect Latin-1 indices.

Parameters

gfx	Target display.
text	CP437-encoded null-terminated string.

Definition at line 421 of file RenderHelpers.cpp.

References cp437ToLatin1().

Referenced by drawText().

◆ drawDialogFrame()

void cdc::ui::render::drawDialogFrame	(	Gdey029T94 *	gfx,
		int	x,
		int	y,
		int	w,
		int	h )

Draws a framed dialog box with double border.

Parameters

gfx	Display drawing context.
x	Left position.
y	Top position.
w	Frame width.
h	Frame height.

Returns: void

Definition at line 205 of file RenderHelpers.cpp.

Referenced by cdc::ui::BlePairingPromptView::render(), cdc::ui::ConfirmView::render(), cdc::ui::ContextMenuView::render(), cdc::ui::MessageBox::render(), and cdc::ui::ToastView::render().

◆ drawFooterBar()

void cdc::ui::render::drawFooterBar	(	Gdey029T94 *	gfx,
		uint16_t	width,
		uint16_t	height,
		const char *	prefix,
		const char *	hint,
		bool	force )

Draws footer bar with optional prefix and hint text.

Parameters

gfx	Display drawing context.
width	Display width.
height	Display height.
prefix	Optional prefix text.
hint	Optional hint text.
force	Draw even if prefix/hint are empty.

Returns: void

Definition at line 118 of file RenderHelpers.cpp.

References FOOTER_HEIGHT.

Referenced by cdc::ui::BlePairingView::render(), cdc::ui::CanvasView::render(), cdc::ui::ColorPickerView::render(), cdc::ui::DateInputView::render(), cdc::ui::ImageView::render(), cdc::ui::InfoView::render(), cdc::ui::ListView::render(), cdc::ui::MarkdownView::render(), cdc::ui::PasswordT9View::render(), cdc::ui::PinChangeView::render(), cdc::ui::PinEntryView::render(), cdc::ui::SliderView::render(), cdc::ui::T9InputView::render(), and cdc::ui::TimeInputView::render().

◆ drawHeaderCentered()

void cdc::ui::render::drawHeaderCentered	(	Gdey029T94 *	gfx,
		const char *	title,
		int	y,
		uint16_t	width )

Draws a centered header title.

Parameters

gfx	Display drawing context.
title	Title text.
y	Header text Y position.
width	Total layout width.

Returns: void

Definition at line 98 of file RenderHelpers.cpp.

Referenced by cdc::ui::BlePairingView::render(), cdc::ui::DateInputView::render(), cdc::ui::PinChangeView::render(), cdc::ui::PinEntryView::render(), cdc::ui::SliderView::render(), and cdc::ui::TimeInputView::render().

◆ drawHeaderLeft()

void cdc::ui::render::drawHeaderLeft	(	Gdey029T94 *	gfx,
		const char *	title,
		int	x,
		int	y,
		uint16_t	width,
		int	underlineOffset = 18 )

Definition at line 79 of file RenderHelpers.cpp.

Referenced by cdc::ui::CanvasView::render(), cdc::ui::InfoView::render(), cdc::ui::ListView::render(), cdc::ui::MarkdownView::render(), cdc::ui::PasswordT9View::render(), and cdc::ui::T9InputView::render().

◆ drawScrollIndicator()

void cdc::ui::render::drawScrollIndicator	(	Gdey029T94 *	gfx,
		int	x,
		int	y,
		int	listHeight,
		uint16_t	totalItems,
		uint16_t	visibleItems,
		uint16_t	scrollPos )

Draws scroll arrows and scrollbar thumb.

Parameters

gfx	Display drawing context.
x	Indicator X position.
y	Indicator Y position.
listHeight	Height of the scrollable list area.
totalItems	Total item count.
visibleItems	Number of visible items.
scrollPos	Current scroll offset.

Returns: void

Definition at line 148 of file RenderHelpers.cpp.

References SCROLL_INDICATOR_WIDTH.

Referenced by cdc::ui::InfoView::render(), cdc::ui::ListView::render(), and cdc::ui::MarkdownView::render().

◆ drawText()

void cdc::ui::render::drawText	(	Adafruit_GFX *	gfx,
		const char *	text,
		const GFXfont *	font )

Draws CP437-encoded text correctly for the given font: the built-in glcdfont (font == nullptr) is CP437-indexed and receives the bytes raw; TTF-derived GFX fonts are Latin-1-indexed and receive a per-byte CP437->Latin1 mapping. This is the single point where the in-memory CP437 canonical form is adapted to the active font's index space. The caller must have set font on gfx and positioned the cursor.

Parameters

gfx	Target display.
text	CP437-encoded null-terminated string.
font	Active font (nullptr for the built-in glcdfont).

Definition at line 428 of file RenderHelpers.cpp.

References drawCp437Text().

Referenced by host_surface_draw_text(), host_surface_draw_text_aligned(), cdc::ui::CanvasView::marquee(), cdc::ui::LockScreenView::render(), and cdc::ui::MarkdownView::render().

◆ fillCircleDither()

void cdc::ui::render::fillCircleDither	(	Adafruit_GFX *	gfx,
		int16_t	cx,
		int16_t	cy,
		int16_t	r,
		uint8_t	shade,
		uint16_t	color )

Dithered filled circle; see fillRectDither.

Definition at line 600 of file RenderHelpers.cpp.

References ditherOn().

Referenced by host_surface_draw_circle().

◆ fillRectDither()

void cdc::ui::render::fillRectDither	(	Adafruit_GFX *	gfx,
		int16_t	x,
		int16_t	y,
		int16_t	w,
		int16_t	h,
		uint8_t	shade,
		uint16_t	color )

Fills a rectangle with an ordered-dither fake-grey pattern.

Parameters

gfx	Target drawing context.
color	Ink color for dithered-on pixels.

Definition at line 537 of file RenderHelpers.cpp.

References ditherOn().

Referenced by host_surface_draw_rect().

◆ fillTriangleDither()

void cdc::ui::render::fillTriangleDither	(	Adafruit_GFX *	gfx,
		int16_t	x0,
		int16_t	y0,
		int16_t	x1,
		int16_t	y1,
		int16_t	x2,
		int16_t	y2,
		uint8_t	shade,
		uint16_t	color )

Dithered filled triangle; see fillRectDither.

Definition at line 613 of file RenderHelpers.cpp.

References ditherOn().

Referenced by host_surface_draw_triangle().

◆ measureCp437Text()

void cdc::ui::render::measureCp437Text	(	Adafruit_GFX *	gfx,
		const char *	text,
		int16_t	x0,
		int16_t	y0,
		int16_t *	x1,
		int16_t *	y1,
		uint16_t *	w,
		uint16_t *	h )

Measures a CP437 string using the current font (via Latin-1 mapping).

Parameters

gfx	Target display.
text	CP437-encoded null-terminated string.
x0	Starting x position for measurement.
y0	Starting y position for measurement.
x1	Output: top-left x of the rendered bounds.
y1	Output: top-left y of the rendered bounds.
w	Output: width of the rendered text.
h	Output: height of the rendered text.

Definition at line 499 of file RenderHelpers.cpp.

References cp437ToLatin1().

Referenced by measureText(), and pickFontThatFits().

◆ measureText()

void cdc::ui::render::measureText	(	Adafruit_GFX *	gfx,
		const char *	text,
		const GFXfont *	font,
		int16_t	x0,
		int16_t	y0,
		int16_t *	x1,
		int16_t *	y1,
		uint16_t *	w,
		uint16_t *	h )

Measures CP437 text exactly as drawText would render it with font, so width-based layout (centering, fitting, truncation) matches the drawn glyphs.

Parameters

gfx	Target display.
text	CP437-encoded null-terminated string.
font	Active font (nullptr for the built-in glcdfont).
x0	Starting x for measurement.
y0	Starting y for measurement.
x1	Output: top-left x of the rendered bounds.
y1	Output: top-left y of the rendered bounds.
w	Output: rendered width.
h	Output: rendered height.

Definition at line 448 of file RenderHelpers.cpp.

References measureCp437Text().

Referenced by host_surface_draw_text_aligned(), host_surface_measure_text(), cdc::ui::CanvasView::marquee(), and cdc::ui::LockScreenView::render().

◆ pickFontThatFits()

const GFXfont * cdc::ui::render::pickFontThatFits	(	Adafruit_GFX *	gfx,
		const char *	text,
		int	maxWidthPx,
		const GFXfont const	candidates,
		size_t	count,
		bool	cp437 = false )

Picks the largest font from candidates whose rendered width of text fits within maxWidthPx. Candidates are evaluated in array order; pass them sorted from largest to smallest so the first match is the biggest font that still fits.

Parameters

gfx	Target display. Its current font is overwritten while measuring and restored to the selected font on return.
text	Null-terminated text to measure.
maxWidthPx	Pixel budget that the rendered text must stay below.
candidates	Array of GFX font pointers. nullptr entries select the built-in 6x8 font.
count	Number of entries in `candidates`.
cp437	If true, measure via measureCp437Text() (CP437->Latin1 mapping); otherwise use Adafruit-GFX getTextBounds() directly.

Returns: Selected font pointer. Falls back to the last (smallest) candidate when nothing fits; returns nullptr if the array is empty.

Definition at line 466 of file RenderHelpers.cpp.

References measureCp437Text().

Referenced by host_text_pick_font_that_fits(), and cdc::ui::LockScreenView::render().

◆ printText()

void cdc::ui::render::printText	(	Adafruit_GFX *	gfx,
		const char *	text )

Draws CP437 text with the built-in 6x8 glyph font, byte-for-byte.

Use this instead of gfx->print(const char*) for any user/i18n string: the CalEPD Epd::print(const std::string&) overload assumes UTF-8 and adds 64 to bytes 0x84..0xBE, corrupting CP437 umlauts (ae 0x84 -> 0xC4 etc.). This forces the built-in font and writes each byte straight through, bypassing that.

Parameters

gfx	Display drawing context.
text	CP437-encoded null-terminated string.

Definition at line 442 of file RenderHelpers.cpp.

◆ printTruncated()

void cdc::ui::render::printTruncated	(	Adafruit_GFX *	gfx,
		const char *	text,
		int	maxWidthPx )

Print text at the current cursor, truncated with an ellipsis to fit maxWidthPx. Caller must have already called setCursor and setTextColor/setTextSize. Adafruit-GFX text wrap should be off.

Draws a left-aligned header with optional underline.

Parameters

gfx	Display drawing context.
text	Null-terminated text.
maxWidthPx	Maximum width in pixels.
gfx	Display drawing context.
title	Optional title text.
x	Header text X position.
y	Header text Y position.
width	Width used for underline.
underlineOffset	Vertical offset for underline.

Returns: void

Definition at line 40 of file RenderHelpers.cpp.

Referenced by cdc::ui::BlePairingView::render(), and cdc::ui::ToastView::render().

◆ utf8ToCp437Inplace()

void cdc::ui::render::utf8ToCp437Inplace ( char * buf )

Decodes a UTF-8 string in place to CP437 single bytes. Truncates if the buffer is too small. Unmapped codepoints are dropped silently.

Parameters

buf	Mutable null-terminated UTF-8 buffer; written back as CP437.

Definition at line 357 of file RenderHelpers.cpp.

References cdc::core::cp437::fromUtf8().

Referenced by decodeWebText().

Variable Documentation

◆ FOOTER_HEIGHT

int cdc::ui::render::FOOTER_HEIGHT = cdc::ui::layout::FOOTER_HEIGHT

constexpr

Definition at line 17 of file RenderHelpers.h.

Referenced by drawFooterBar().

◆ SCROLL_INDICATOR_WIDTH

int cdc::ui::render::SCROLL_INDICATOR_WIDTH = cdc::ui::layout::SCROLL_INDICATOR_WIDTH

constexpr

Definition at line 18 of file RenderHelpers.h.

Referenced by drawScrollIndicator().

Classes

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ DisplayTarget

Function Documentation

◆ cp437ToLatin1()

◆ decodeWebText()

◆ ditherOn()

◆ drawBitmapMasked()

◆ drawCp437Text()

◆ drawDialogFrame()

◆ drawFooterBar()

◆ drawHeaderCentered()

◆ drawHeaderLeft()

◆ drawScrollIndicator()

◆ drawText()

◆ fillCircleDither()

◆ fillRectDither()

◆ fillTriangleDither()

◆ measureCp437Text()

◆ measureText()

◆ pickFontThatFits()

◆ printText()

◆ printTruncated()

◆ utf8ToCp437Inplace()

Variable Documentation

◆ FOOTER_HEIGHT

◆ SCROLL_INDICATOR_WIDTH