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	self.X = x
243	self.Y = y
244	self.Width = width
245	self.Height = height + self.Padding.Bottom
246	(*state)[n.Properties.Id] = self
247
248	if !utils.ChildrenHaveText(n) && len(n.InnerText) > 0 {
249		// Confirm text exists
250		words := strings.Split(strings.TrimSpace(n.InnerText), " ")
251		if len(words) != 1 {
252			if n.Style["display"] == "inline" {
253				n.InnerText = words[0]
254				el := *n
255				el.InnerText = strings.Join(words[1:], " ")
256				n.Parent.InsertAfter(el, *n)
257			}
258			// !ISSUE: change genTextNode to basically a image generator for a word.
259			// + make it so this api can be used to also do images
260			// + element.State.Texture?
261		}
262		if len(strings.TrimSpace(n.InnerText)) > 0 {
263			n.InnerText = strings.TrimSpace(n.InnerText)
264			self = genTextNode(n, state)
265		}
266	}
267
268	(*state)[n.Properties.Id] = self
269	(*state)[n.Parent.Properties.Id] = parent
270
271	// Call children here
272
273	var childYOffset float32
274	for i := 0; i < len(n.Children); i++ {
275		v := n.Children[i]
276		v.Parent = n
277		n.Children[i] = *c.ComputeNodeStyle(&v, state)
278		cState := (*state)[n.Children[i].Properties.Id]
279		if n.Style["height"] == "" {
280			if n.Children[i].Style["position"] != "absolute" && cState.Y > childYOffset {
281				childYOffset = cState.Y
282				self.Height += cState.Height
283				self.Height += cState.Margin.Top
284				self.Height += cState.Margin.Bottom
285				self.Height += cState.Padding.Top
286				self.Height += cState.Padding.Bottom
287			}
288		}
289		// fmt.Println(n.TagName, self.Width, v.TagName, cState.Width)
290		if cState.Width > self.Width {
291			self.Width = cState.Width
292		}
293	}
294
295	(*state)[n.Properties.Id] = self
296
297	// Sorting the array by the Level field
298	sort.Slice(plugins, func(i, j int) bool {
299		return plugins[i].Level < plugins[j].Level
300	})
301
302	for _, v := range plugins {
303		matches := true
304		for name, value := range v.Styles {
305			if n.Style[name] != value && !(value == "*") {
306				matches = false
307			}
308		}
309		if matches {
310			v.Handler(n, state)
311		}
312	}
313
314	for i := range n.Children {
315		cState := (*state)[n.Children[i].Properties.Id]
316		cState.Y += self.Padding.Top
317		(*state)[n.Children[i].Properties.Id] = cState
318	}
319
320	// CheckNode(n, state)
321
322	return n
323}
324
325func parseBorderShorthand(borderShorthand string) (element.Border, error) {
326	// Split the shorthand into components
327	borderComponents := strings.Fields(borderShorthand)
328
329	// Ensure there are at least 1 component (width or style or color)
330	if len(borderComponents) >= 1 {
331		width := "0px" // Default width
332		style := "solid"
333		borderColor := "#000000" // Default color
334
335		// Extract style and color if available
336		if len(borderComponents) >= 1 {
337			width = borderComponents[0]
338		}
339
340		// Extract style and color if available
341		if len(borderComponents) >= 2 {
342			style = borderComponents[1]
343		}
344		if len(borderComponents) >= 3 {
345			borderColor = borderComponents[2]
346		}
347
348		parsedColor, _ := color.Color(borderColor)
349
350		return element.Border{
351			Width:  width,
352			Style:  style,
353			Color:  parsedColor,
354			Radius: "", // Default radius
355		}, nil
356	}
357
358	return element.Border{}, fmt.Errorf("invalid border shorthand format")
359}
360
361func CompleteBorder(cssProperties map[string]string) (element.Border, error) {
362	border, err := parseBorderShorthand(cssProperties["border"])
363	border.Radius = cssProperties["border-radius"]
364
365	return border, err
366}
367
368func genTextNode(n *element.Node, state *map[string]element.State) element.State {
369	s := *state
370	self := s[n.Properties.Id]
371	parent := s[n.Parent.Properties.Id]
372
373	bold, italic := false, false
374
375	if n.Style["font-weight"] == "bold" {
376		bold = true
377	}
378
379	if n.Style["font-style"] == "italic" {
380		italic = true
381	}
382
383	if self.Text.Font == nil {
384		f, _ := font.LoadFont(n.Style["font-family"], int(self.EM), bold, italic)
385		self.Text.Font = f
386	}
387
388	letterSpacing, _ := utils.ConvertToPixels(n.Style["letter-spacing"], self.EM, parent.Width)
389	wordSpacing, _ := utils.ConvertToPixels(n.Style["word-spacing"], self.EM, parent.Width)
390	lineHeight, _ := utils.ConvertToPixels(n.Style["line-height"], self.EM, parent.Width)
391	if lineHeight == 0 {
392		lineHeight = self.EM + 3
393	}
394
395	self.Text.LineHeight = int(lineHeight)
396	self.Text.WordSpacing = int(wordSpacing)
397	self.Text.LetterSpacing = int(letterSpacing)
398	wb := " "
399
400	if n.Style["word-wrap"] == "break-word" {
401		wb = ""
402	}
403
404	if n.Style["text-wrap"] == "wrap" || n.Style["text-wrap"] == "balance" {
405		wb = ""
406	}
407
408	var dt float32
409
410	if n.Style["text-decoration-thickness"] == "auto" || n.Style["text-decoration-thickness"] == "" {
411		dt = 3
412	} else {
413		dt, _ = utils.ConvertToPixels(n.Style["text-decoration-thickness"], self.EM, parent.Width)
414	}
415
416	col := color.Parse(n.Style, "font")
417
418	self.Text.Color = col
419	self.Text.DecorationColor = color.Parse(n.Style, "decoration")
420	self.Text.Align = n.Style["text-align"]
421	self.Text.WordBreak = wb
422	self.Text.WordSpacing = int(wordSpacing)
423	self.Text.LetterSpacing = int(letterSpacing)
424	self.Text.WhiteSpace = n.Style["white-space"]
425	self.Text.DecorationThickness = int(dt)
426	self.Text.Overlined = n.Style["text-decoration"] == "overline"
427	self.Text.Underlined = n.Style["text-decoration"] == "underline"
428	self.Text.LineThrough = n.Style["text-decoration"] == "linethrough"
429	self.Text.EM = int(self.EM)
430	self.Text.Width = int(parent.Width)
431	self.Text.Text = n.InnerText
432
433	if n.Style["word-spacing"] == "" {
434		self.Text.WordSpacing = font.MeasureSpace(&self.Text)
435	}
436
437	img, width := font.Render(&self)
438	self.Text.Image = img
439	self.Text.Width = int(width)
440	self.Width = float32(width)
441
442	if n.Style["height"] == "" {
443		self.Height = float32(self.Text.LineHeight)
444	}
445
446	return self
447}