CStyle

CStyle is a single pass style computer.

# StyleSheet?(go)

# StyleTag?(go)

# GetStyles?(go)

# AddPlugin?(go)

See /cstyle/plugins/

# ComputeNodeStyle?(go)

if !utils.ChildrenHaveText(n) The utils.ChildrenHaveText function is called here instead of checking if the node directly has text is because in the case below

1<em><b>Text</b></em>

The em element does not have text but it has a element with text insid, but the element will still need to be rendered as text.

# parseBorderShorthand?(go)

# CompleteBorder?(go)

# genTextNode?(go)

  1package cstyle
  2
  3// package aui/goldie
  4// https://pkg.go.dev/automated.sh/goldie
  5// https://pkg.go.dev/automated.sh/aui
  6// https://pkg.go.dev/automated.sh/oat
  7
  8import (
  9	"fmt"
 10	"gui/color"
 11	"gui/element"
 12	"gui/font"
 13	"gui/parser"
 14	"gui/utils"
 15	"os"
 16	"slices"
 17	"sort"
 18	"strings"
 19)
 20
 21type Plugin struct {
 22	Styles  map[string]string
 23	Level   int
 24	Handler func(*element.Node, *map[string]element.State)
 25}
 26
 27type CSS struct {
 28	Width       float32
 29	Height      float32
 30	StyleSheets []map[string]map[string]string
 31	Plugins     []Plugin
 32	Document    *element.Node
 33}
 34
 35func (c *CSS) StyleSheet(path string) {
 36	// Parse the CSS file
 37	dat, err := os.ReadFile(path)
 38	utils.Check(err)
 39	styles := parser.ParseCSS(string(dat))
 40
 41	c.StyleSheets = append(c.StyleSheets, styles)
 42}
 43
 44func (c *CSS) StyleTag(css string) {
 45	styles := parser.ParseCSS(css)
 46	c.StyleSheets = append(c.StyleSheets, styles)
 47}
 48
 49var inheritedProps = []string{
 50	"color",
 51	"cursor",
 52	"font",
 53	"font-family",
 54	"font-size",
 55	"font-style",
 56	"font-weight",
 57	"letter-spacing",
 58	"line-height",
 59	"text-align",
 60	"text-indent",
 61	"text-justify",
 62	"text-shadow",
 63	"text-transform",
 64	"visibility",
 65	"word-spacing",
 66	"display",
 67}
 68
 69func (c *CSS) GetStyles(n element.Node) map[string]string {
 70	styles := map[string]string{}
 71
 72	if n.Parent != nil {
 73		ps := c.GetStyles(*n.Parent)
 74		for _, v := range inheritedProps {
 75			if ps[v] != "" {
 76				styles[v] = ps[v]
 77			}
 78		}
 79	}
 80	for k, v := range n.Style {
 81		styles[k] = v
 82	}
 83	hovered := false
 84	if slices.Contains(n.ClassList.Classes, ":hover") {
 85		hovered = true
 86	}
 87
 88	for _, styleSheet := range c.StyleSheets {
 89		for selector := range styleSheet {
 90			// fmt.Println(selector, n.Properties.Id)
 91			key := selector
 92			if strings.Contains(selector, ":hover") && hovered {
 93				selector = strings.Replace(selector, ":hover", "", -1)
 94			}
 95			if element.TestSelector(selector, &n) {
 96				for k, v := range styleSheet[key] {
 97					styles[k] = v
 98				}
 99			}
100
101		}
102	}
103
104	// !ISSUE: why is this needed, the "attribute" is n.Style that should be mapped during init
105	// + when a user adds a style via the style attirbute it will just be in the .Style prop...
106	inline := parser.ParseStyleAttribute(n.GetAttribute("style") + ";")
107	styles = utils.Merge(styles, inline)
108	// add hover and focus css events
109
110	return styles
111}
112
113func (c *CSS) AddPlugin(plugin Plugin) {
114	c.Plugins = append(c.Plugins, plugin)
115}
116
117func CheckNode(n *element.Node, state *map[string]element.State) {
118	s := *state
119	self := s[n.Properties.Id]
120
121	fmt.Println(n.TagName, n.Properties.Id)
122	fmt.Printf("ID: %v\n", n.Id)
123	fmt.Printf("Parent: %v\n", n.Parent.TagName)
124	fmt.Printf("Classes: %v\n", n.ClassList.Classes)
125	fmt.Printf("Text: %v\n", self.Text.Text)
126	fmt.Printf("X: %v, Y: %v\n", self.X, self.Y)
127	fmt.Printf("Width: %v, Height: %v\n", self.Width, self.Height)
128	fmt.Printf("Styles: %v\n", n.Style)
129	fmt.Printf("Background: %v\n", self.Background)
130	fmt.Printf("Border: %v\n\n\n", self.Border)
131}
132
133func (c *CSS) ComputeNodeStyle(n *element.Node, state *map[string]element.State) *element.Node {
134	// Head is not renderable
135	if utils.IsParent(*n, "head") {
136		return n
137	}
138	plugins := c.Plugins
139	// !ISSUE: This should add to state.Style instead as the element.Node should be un effected by the engine
140	// + currently this adds styles to the style attribute that the use did not explisitly set
141	// + this also applies to the margin/padding and border completer functions
142
143	n.Style = c.GetStyles(*n)
144	s := *state
145	self := s[n.Properties.Id]
146	parent := s[n.Parent.Properties.Id]
147
148	self.Background = color.Parse(n.Style, "background")
149	self.Border, _ = CompleteBorder(n.Style)
150
151	fs, _ := utils.ConvertToPixels(n.Style["font-size"], parent.EM, parent.Width)
152	self.EM = fs
153
154	if n.Style["display"] == "none" {
155		self.X = 0
156		self.Y = 0
157		self.Width = 0
158		self.Height = 0
159		return n
160	}
161
162	wh := utils.GetWH(*n)
163	width := wh.Width
164	height := wh.Height
165
166	x, y := parent.X, parent.Y
167
168	var top, left, right, bottom bool = false, false, false, false
169
170	m := utils.GetMP(*n, "margin")
171	p := utils.GetMP(*n, "padding")
172
173	self.Margin = m
174	self.Padding = p
175
176	if n.Style["position"] == "absolute" {
177		bas := utils.GetPositionOffsetNode(n)
178		base := s[bas.Properties.Id]
179		if n.Style["top"] != "" {
180			v, _ := utils.ConvertToPixels(n.Style["top"], self.EM, parent.Width)
181			y = v + base.Y
182			top = true
183		}
184		if n.Style["left"] != "" {
185			v, _ := utils.ConvertToPixels(n.Style["left"], self.EM, parent.Width)
186			x = v + base.X
187			left = true
188		}
189		if n.Style["right"] != "" {
190			v, _ := utils.ConvertToPixels(n.Style["right"], self.EM, parent.Width)
191			x = (base.Width - width) - v
192			right = true
193		}
194		if n.Style["bottom"] != "" {
195			v, _ := utils.ConvertToPixels(n.Style["bottom"], self.EM, parent.Width)
196			y = (base.Height - height) - v
197			bottom = true
198		}
199	} else {
200		for i, v := range n.Parent.Children {
201			if v.Properties.Id == n.Properties.Id {
202				if i-1 > 0 {
203					sib := n.Parent.Children[i-1]
204					sibling := s[sib.Properties.Id]
205					if n.Style["display"] == "inline" {
206						if sib.Style["display"] == "inline" {
207							y = sibling.Y
208						} else {
209							y = sibling.Y + sibling.Height
210						}
211					} else {
212						y = sibling.Y + sibling.Height
213					}
214				}
215				break
216			} else if n.Style["display"] != "inline" {
217				vState := s[v.Properties.Id]
218				y += vState.Margin.Top + vState.Margin.Bottom + vState.Padding.Top + vState.Padding.Bottom + vState.Height
219			}
220		}
221	}
222
223	// Display modes need to be calculated here
224
225	relPos := !top && !left && !right && !bottom
226
227	if left || relPos {
228		x += m.Left
229	}
230	if top || relPos {
231		y += m.Top
232	}
233	if right {
234		x -= m.Right
235	}
236	if bottom {
237		y -= m.Bottom
238	}
239
240	// fmt.Println(n.InnerText, len(n.Children))
241
242	if !utils.ChildrenHaveText(n) {
243		// Confirm text exists
244		if len(n.InnerText) > 0 {
245			words := strings.Split(n.InnerText, " ")
246			if len(words) != 1 && !strings.Contains(n.Properties.Id, "copy") && n.Style["display"] == "inline" {
247				n.InnerText = words[0]
248				n.Properties.Id = "copy" + n.Properties.Id
249				// slices.Reverse(words)
250				// !ISSUE: I thinkthis is a good route to take, might make a style prop for text that a plugins can be used to turn the groups
251				// + into psuedo elements but make them inline
252				// + that would take care of wrapping and it would also work for display block
253				for _, v := range words {
254					if len(strings.TrimSpace(v)) > 0 {
255						el := *n
256						el.InnerText = v
257						for k, val := range n.Style {
258							el.Style[k] = val
259						}
260						n.Parent.InsertAfter(el, *n)
261					}
262				}
263				// !ISSUE: can probally use flex to do it need to group text so it doesn't include block element
264				// + if there is a block element break then go on
265				// fmt.Println(n.Parent.Children)
266			}
267			innerWidth := width
268			innerHeight := height
269			(*state)[n.Properties.Id] = self
270			// !ISSUE: change genTextNode to basically a image generator for a word.
271			// + make it so this api can be used to also do images
272			self = genTextNode(n, &innerWidth, &innerHeight, p, state)
273			width = innerWidth + p.Left + p.Right
274			height = innerHeight
275		}
276	}
277
278	// if !utils.ChildrenHaveText(n) {
279	// 	// Confirm text exists
280	// 	if len(n.InnerText) > 0 {
281	// 		innerWidth := width
282	// 		innerHeight := height
283	// 		(*state)[n.Properties.Id] = self
284	// 		self = genTextNode(n, &innerWidth, &innerHeight, p, state)
285	// 		width = innerWidth + p.Left + p.Right
286	// 		height = innerHeight
287	// 	}
288	// }
289
290	self.X = x
291	self.Y = y
292	self.Width = width
293	self.Height = height
294
295	(*state)[n.Properties.Id] = self
296	(*state)[n.Parent.Properties.Id] = parent
297
298	// Call children here
299
300	var childYOffset float32
301	for i, v := range n.Children {
302		v.Parent = n
303		n.Children[i] = *c.ComputeNodeStyle(&v, state)
304		cState := (*state)[n.Children[i].Properties.Id]
305		if n.Style["height"] == "" {
306			if n.Children[i].Style["position"] != "absolute" && cState.Y > childYOffset {
307				childYOffset = cState.Y
308				self.Height += cState.Height
309				self.Height += cState.Margin.Top
310				self.Height += cState.Margin.Bottom
311				self.Height += cState.Padding.Top
312				self.Height += cState.Padding.Bottom
313			}
314		}
315		// fmt.Println(n.TagName, self.Width, v.TagName, cState.Width)
316		if cState.Width > self.Width {
317			self.Width = cState.Width
318		}
319	}
320
321	(*state)[n.Properties.Id] = self
322
323	// Sorting the array by the Level field
324	sort.Slice(plugins, func(i, j int) bool {
325		return plugins[i].Level < plugins[j].Level
326	})
327
328	for _, v := range plugins {
329		matches := true
330		for name, value := range v.Styles {
331			if n.Style[name] != value && !(value == "*") {
332				matches = false
333			}
334		}
335		if matches {
336			v.Handler(n, state)
337		}
338	}
339
340	CheckNode(n, state)
341
342	return n
343}
344
345func parseBorderShorthand(borderShorthand string) (element.Border, error) {
346	// Split the shorthand into components
347	borderComponents := strings.Fields(borderShorthand)
348
349	// Ensure there are at least 1 component (width or style or color)
350	if len(borderComponents) >= 1 {
351		width := "0px" // Default width
352		style := "solid"
353		borderColor := "#000000" // Default color
354
355		// Extract style and color if available
356		if len(borderComponents) >= 1 {
357			width = borderComponents[0]
358		}
359
360		// Extract style and color if available
361		if len(borderComponents) >= 2 {
362			style = borderComponents[1]
363		}
364		if len(borderComponents) >= 3 {
365			borderColor = borderComponents[2]
366		}
367
368		parsedColor, _ := color.Color(borderColor)
369
370		return element.Border{
371			Width:  width,
372			Style:  style,
373			Color:  parsedColor,
374			Radius: "", // Default radius
375		}, nil
376	}
377
378	return element.Border{}, fmt.Errorf("invalid border shorthand format")
379}
380
381func CompleteBorder(cssProperties map[string]string) (element.Border, error) {
382	border, err := parseBorderShorthand(cssProperties["border"])
383	border.Radius = cssProperties["border-radius"]
384
385	return border, err
386}
387
388func genTextNode(n *element.Node, width, height *float32, p element.MarginPadding, state *map[string]element.State) element.State {
389	s := *state
390	self := s[n.Properties.Id]
391	parent := s[n.Parent.Properties.Id]
392
393	bold, italic := false, false
394
395	if n.Style["font-weight"] == "bold" {
396		bold = true
397	}
398
399	if n.Style["font-style"] == "italic" {
400		italic = true
401	}
402
403	if self.Text.Font == nil {
404		f, _ := font.LoadFont(n.Style["font-family"], int(self.EM), bold, italic)
405		self.Text.Font = f
406	}
407
408	letterSpacing, _ := utils.ConvertToPixels(n.Style["letter-spacing"], self.EM, *width)
409	wordSpacing, _ := utils.ConvertToPixels(n.Style["word-spacing"], self.EM, *width)
410	lineHeight, _ := utils.ConvertToPixels(n.Style["line-height"], self.EM, *width)
411	if lineHeight == 0 {
412		lineHeight = self.EM + 3
413	}
414
415	self.Text.LineHeight = int(lineHeight)
416	self.Text.WordSpacing = int(wordSpacing)
417	self.Text.LetterSpacing = int(letterSpacing)
418	wb := " "
419
420	if n.Style["word-wrap"] == "break-word" {
421		wb = ""
422	}
423
424	if n.Style["text-wrap"] == "wrap" || n.Style["text-wrap"] == "balance" {
425		wb = ""
426	}
427
428	var dt float32
429
430	if n.Style["text-decoration-thickness"] == "auto" || n.Style["text-decoration-thickness"] == "" {
431		dt = 3
432	} else {
433		dt, _ = utils.ConvertToPixels(n.Style["text-decoration-thickness"], self.EM, *width)
434	}
435
436	col := color.Parse(n.Style, "font")
437
438	self.Text.Color = col
439	self.Text.DecorationColor = color.Parse(n.Style, "decoration")
440	self.Text.Align = n.Style["text-align"]
441	self.Text.WordBreak = wb
442	self.Text.WordSpacing = int(wordSpacing)
443	self.Text.LetterSpacing = int(letterSpacing)
444	self.Text.WhiteSpace = n.Style["white-space"]
445	self.Text.DecorationThickness = int(dt)
446	self.Text.Overlined = n.Style["text-decoration"] == "overline"
447	self.Text.Underlined = n.Style["text-decoration"] == "underline"
448	self.Text.LineThrough = n.Style["text-decoration"] == "linethrough"
449	self.Text.EM = int(self.EM)
450	self.Text.Width = int(parent.Width)
451	self.Text.Text = n.InnerText
452
453	if n.Style["word-spacing"] == "" {
454		self.Text.WordSpacing = font.MeasureSpace(&self.Text)
455	}
456	if parent.Width != 0 && n.Style["display"] != "inline" && n.Style["width"] == "" {
457		*width = (parent.Width - p.Right) - p.Left
458	} else if n.Style["width"] == "" {
459		*width = utils.Max(*width, float32(font.MeasureLongest(&self)))
460	} else if n.Style["width"] != "" {
461		*width, _ = utils.ConvertToPixels(n.Style["width"], self.EM, parent.Width)
462	}
463
464	self.Text.Width = int(*width)
465	self.Width = *width
466	h := font.Render(&self)
467	if n.Style["height"] == "" {
468		*height = h
469	}
470
471	return self
472
473}