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
  3import (
  4	"fmt"
  5	"gui/color"
  6	"gui/element"
  7	"gui/font"
  8	"gui/parser"
  9	"gui/utils"
 10	"os"
 11	"slices"
 12	"sort"
 13	"strconv"
 14	"strings"
 15)
 16
 17type Plugin struct {
 18	Styles  map[string]string
 19	Level   int
 20	Handler func(*element.Node, *map[string]element.State)
 21}
 22
 23type CSS struct {
 24	Width       float32
 25	Height      float32
 26	StyleSheets []map[string]map[string]string
 27	Plugins     []Plugin
 28	Document    *element.Node
 29}
 30
 31func (c *CSS) StyleSheet(path string) {
 32	// Parse the CSS file
 33	dat, err := os.ReadFile(path)
 34	utils.Check(err)
 35	styles := parser.ParseCSS(string(dat))
 36
 37	c.StyleSheets = append(c.StyleSheets, styles)
 38}
 39
 40func (c *CSS) StyleTag(css string) {
 41	styles := parser.ParseCSS(css)
 42	c.StyleSheets = append(c.StyleSheets, styles)
 43}
 44
 45var inheritedProps = []string{
 46	"color",
 47	"cursor",
 48	"font",
 49	"font-family",
 50	"font-size",
 51	"font-style",
 52	"font-weight",
 53	"letter-spacing",
 54	"line-height",
 55	// "text-align",
 56	"text-indent",
 57	"text-justify",
 58	"text-shadow",
 59	"text-transform",
 60	"text-decoration",
 61	"visibility",
 62	"word-spacing",
 63	"display",
 64}
 65
 66func (c *CSS) GetStyles(n element.Node) map[string]string {
 67	styles := map[string]string{}
 68
 69	if n.Parent != nil {
 70		ps := c.GetStyles(*n.Parent)
 71		for _, v := range inheritedProps {
 72			if ps[v] != "" {
 73				styles[v] = ps[v]
 74			}
 75		}
 76	}
 77	for k, v := range n.Style {
 78		styles[k] = v
 79	}
 80	hovered := false
 81	if slices.Contains(n.ClassList.Classes, ":hover") {
 82		hovered = true
 83	}
 84
 85	for _, styleSheet := range c.StyleSheets {
 86		for selector := range styleSheet {
 87			// fmt.Println(selector, n.Properties.Id)
 88			key := selector
 89			if strings.Contains(selector, ":hover") && hovered {
 90				selector = strings.Replace(selector, ":hover", "", -1)
 91			}
 92			if element.TestSelector(selector, &n) {
 93				for k, v := range styleSheet[key] {
 94					styles[k] = v
 95				}
 96			}
 97
 98		}
 99	}
100
101	// This is different than node.Style
102	// temp1 = <span style=​"color:​#a6e22e">​CSS​</span>​
103	// temp1.style == CSSStyleDeclaration {0: 'color', accentColor: '', additiveSymbols: '', alignContent: '', alignItems: '', alignSelf: '', …}
104	// temp1.getAttribute("style") == 'color:#a6e22e'
105	inline := parser.ParseStyleAttribute(n.GetAttribute("style") + ";")
106	styles = utils.Merge(styles, inline)
107	// add hover and focus css events
108
109	if n.Parent != nil {
110		if styles["z-index"] == "" && n.Parent.Style["z-index"] != "" {
111			z, _ := strconv.Atoi(n.Parent.Style["z-index"])
112			z += 1
113			styles["z-index"] = strconv.Itoa(z)
114		}
115	}
116
117	return styles
118}
119
120func (c *CSS) AddPlugin(plugin Plugin) {
121	c.Plugins = append(c.Plugins, plugin)
122}
123
124func CheckNode(n *element.Node, state *map[string]element.State) {
125	s := *state
126	self := s[n.Properties.Id]
127
128	fmt.Println(n.TagName, n.Properties.Id)
129	fmt.Printf("ID: %v\n", n.Id)
130	fmt.Printf("EM: %v\n", self.EM)
131	fmt.Printf("Parent: %v\n", n.Parent.TagName)
132	fmt.Printf("Classes: %v\n", n.ClassList.Classes)
133	fmt.Printf("Text: %v\n", n.InnerText)
134	fmt.Printf("X: %v, Y: %v, Z: %v\n", self.X, self.Y, self.Z)
135	fmt.Printf("Width: %v, Height: %v\n", self.Width, self.Height)
136	fmt.Printf("Styles: %v\n", self.Style)
137	fmt.Printf("Background: %v\n", self.Background)
138	fmt.Printf("Border: %v\n\n\n", self.Border)
139}
140
141func (c *CSS) ComputeNodeStyle(node *element.Node, state *map[string]element.State) *element.Node {
142
143	// Head is not renderable
144	if utils.IsParent(*node, "head") {
145		return node
146	}
147
148	// !TODO: Make a plugin type system that can rewrite nodes and matches by more than just tagname
149	// + should be ran here once a node is loaded
150	plugins := c.Plugins
151
152	s := *state
153	self := s[node.Properties.Id]
154	parent := s[node.Parent.Properties.Id]
155
156	var n *element.Node
157
158	// !ISSUE: For some reason node is still being tainted
159	// + if the user changes the innerText of the swap parent then how does the swap get updated????
160	// + in theory it should be invalided when the main invalidator runs
161	if self.Swap.Properties.Id != "" {
162		n = &self.Swap
163		// fmt.Println("Swapped: ", n.Properties.Id, n.InnerText)
164		// CheckNode(node, state)
165		// CheckNode(&self.Swap, state)
166	} else {
167		n = node
168		// fmt.Println("Back: ", n.Properties.Id, n.InnerText)
169		self.Style = c.GetStyles(*n)
170	}
171
172	self.Background = color.Parse(self.Style, "background")
173	self.Border, _ = CompleteBorder(self.Style, self, parent)
174
175	fs, _ := utils.ConvertToPixels(self.Style["font-size"], parent.EM, parent.Width)
176	self.EM = fs
177
178	if self.Style["display"] == "none" {
179		self.X = 0
180		self.Y = 0
181		self.Width = 0
182		self.Height = 0
183		return n
184	}
185
186	if self.Style["width"] == "" && self.Style["display"] == "block" {
187		self.Style["width"] = "100%"
188	}
189
190	// Set Z index value to be sorted in window
191	if self.Style["z-index"] != "" {
192		z, _ := strconv.Atoi(self.Style["z-index"])
193		self.Z = float32(z)
194	}
195
196	if parent.Z > 0 {
197		self.Z = parent.Z + 1
198	}
199
200	(*state)[n.Properties.Id] = self
201
202	wh := utils.GetWH(*n, state)
203	width := wh.Width
204	height := wh.Height
205
206	x, y := parent.X, parent.Y
207	offsetX, offsetY := utils.GetXY(n, state)
208	x += offsetX
209	y += offsetY
210
211	// !NOTE: Maybe make a get xy offset function...
212
213	var top, left, right, bottom bool = false, false, false, false
214
215	m := utils.GetMP(*n, wh, state, "margin")
216	p := utils.GetMP(*n, wh, state, "padding")
217
218	self.Margin = m
219	self.Padding = p
220
221	if self.Style["position"] == "absolute" {
222		bas := utils.GetPositionOffsetNode(n, state)
223		base := s[bas.Properties.Id]
224		if self.Style["top"] != "" {
225			v, _ := utils.ConvertToPixels(self.Style["top"], self.EM, parent.Width)
226			y = v + base.Y
227			top = true
228		}
229		if self.Style["left"] != "" {
230			v, _ := utils.ConvertToPixels(self.Style["left"], self.EM, parent.Width)
231			x = v + base.X
232			left = true
233		}
234		if self.Style["right"] != "" {
235			v, _ := utils.ConvertToPixels(self.Style["right"], self.EM, parent.Width)
236			x = (base.Width - width) - v
237			right = true
238		}
239		if self.Style["bottom"] != "" {
240			v, _ := utils.ConvertToPixels(self.Style["bottom"], self.EM, parent.Width)
241			y = (base.Height - height) - v
242			bottom = true
243		}
244
245	} else {
246		for i, v := range n.Parent.Children {
247			vState := s[v.Properties.Id]
248			if vState.Style["position"] != "absolute" {
249				if v.Properties.Id == n.Properties.Id {
250					if i-1 > 0 {
251						sib := n.Parent.Children[i-1]
252						sibling := s[sib.Properties.Id]
253						if sibling.Style["position"] != "absolute" {
254							if self.Style["display"] == "inline" {
255								if sibling.Style["display"] == "inline" {
256									y = sibling.Y
257								} else {
258									y = sibling.Y + sibling.Height
259								}
260							} else {
261								y = sibling.Y + sibling.Height + (sibling.Border.Width * 2) + sibling.Margin.Bottom
262							}
263						}
264
265					}
266					break
267				} else if self.Style["display"] != "inline" {
268					vState := s[v.Properties.Id]
269					y += vState.Margin.Top + vState.Margin.Bottom + vState.Padding.Top + vState.Padding.Bottom + vState.Height + (self.Border.Width)
270				}
271			}
272		}
273	}
274
275	// Display modes need to be calculated here
276
277	relPos := !top && !left && !right && !bottom
278
279	if left || relPos {
280		x += m.Left
281	}
282	if top || relPos {
283		y += m.Top
284	}
285	if right {
286		x -= m.Right
287	}
288	if bottom {
289		y -= m.Bottom
290	}
291
292	self.X = x
293	self.Y = y
294	self.Width = width
295	self.Height = height
296	(*state)[n.Properties.Id] = self
297
298	if !utils.ChildrenHaveText(n) && len(n.InnerText) > 0 {
299		// Confirm text exists
300		words := strings.Split(strings.TrimSpace(n.InnerText), " ")
301		if len(words) != 1 {
302			// !ISSUE: Still doesn't work great
303			if self.Swap.Properties.Id == "" {
304				self.Swap = *n
305				n = &self.Swap
306			}
307			if self.Style["display"] == "inline" {
308				n.InnerText = words[0]
309				el := *n
310				el.InnerText = strings.Join(words[1:], " ")
311				n.Parent.InsertAfter(el, *n)
312			} else {
313				el := n.CreateElement("notaspan")
314				el.InnerText = n.InnerText
315				n.AppendChild(el)
316				self.Style["font-size"] = parent.Style["font-size"]
317				self.EM = parent.EM
318				n.InnerText = ""
319			}
320			(*state)[n.Properties.Id] = self
321		}
322		if len(strings.TrimSpace(n.InnerText)) > 0 {
323			n.InnerText = strings.TrimSpace(n.InnerText)
324			self = genTextNode(n, state)
325		}
326	}
327
328	(*state)[n.Properties.Id] = self
329	(*state)[n.Parent.Properties.Id] = parent
330
331	// Call children here
332
333	var childYOffset float32
334	for i := 0; i < len(n.Children); i++ {
335		v := n.Children[i]
336		v.Parent = n
337		n.Children[i] = *c.ComputeNodeStyle(&v, state)
338
339		cState := (*state)[n.Children[i].Properties.Id]
340		if self.Style["height"] == "" {
341			if cState.Style["position"] != "absolute" && cState.Y+cState.Height > childYOffset {
342				childYOffset = cState.Y + cState.Height
343				self.Height = (cState.Y - self.Border.Width) - (self.Y) + cState.Height
344				self.Height += cState.Margin.Top
345				self.Height += cState.Margin.Bottom
346				self.Height += cState.Padding.Top
347				self.Height += cState.Padding.Bottom
348			}
349		}
350		if cState.Width > self.Width {
351			self.Width = cState.Width
352		}
353	}
354
355	self.Height += self.Padding.Bottom
356
357	(*state)[n.Properties.Id] = self
358
359	// Sorting the array by the Level field
360	sort.Slice(plugins, func(i, j int) bool {
361		return plugins[i].Level < plugins[j].Level
362	})
363
364	for _, v := range plugins {
365		matches := true
366		for name, value := range v.Styles {
367			if self.Style[name] != value && !(value == "*") {
368				matches = false
369			}
370		}
371		if matches {
372			// !NOTE: Might save memory by making a state map tree and passing that instead of the node it's self
373			v.Handler(n, state)
374		}
375	}
376
377	// CheckNode(n, state)
378
379	return n
380}
381
382func CompleteBorder(cssProperties map[string]string, self, parent element.State) (element.Border, error) {
383	// Split the shorthand into components
384	borderComponents := strings.Fields(cssProperties["border"])
385
386	// Ensure there are at least 1 component (width or style or color)
387	if len(borderComponents) >= 1 {
388		width := "0px" // Default width
389		style := "solid"
390		borderColor := "#000000" // Default color
391
392		// Extract style and color if available
393		if len(borderComponents) >= 1 {
394			width = borderComponents[0]
395		}
396
397		// Extract style and color if available
398		if len(borderComponents) >= 2 {
399			style = borderComponents[1]
400		}
401		if len(borderComponents) >= 3 {
402			borderColor = borderComponents[2]
403		}
404
405		parsedColor, _ := color.Color(borderColor)
406
407		w, _ := utils.ConvertToPixels(width, self.EM, parent.Width)
408
409		return element.Border{
410			Width:  w,
411			Style:  style,
412			Color:  parsedColor,
413			Radius: cssProperties["border-radius"],
414		}, nil
415	}
416
417	return element.Border{}, fmt.Errorf("invalid border shorthand format")
418}
419
420func genTextNode(n *element.Node, state *map[string]element.State) element.State {
421	s := *state
422	self := s[n.Properties.Id]
423	parent := s[n.Parent.Properties.Id]
424
425	text := element.Text{}
426
427	bold, italic := false, false
428
429	if self.Style["font-weight"] == "bold" {
430		bold = true
431	}
432
433	if self.Style["font-style"] == "italic" {
434		italic = true
435	}
436
437	if text.Font == nil {
438		f, _ := font.LoadFont(self.Style["font-family"], int(self.EM), bold, italic)
439		text.Font = f
440	}
441
442	letterSpacing, _ := utils.ConvertToPixels(self.Style["letter-spacing"], self.EM, parent.Width)
443	wordSpacing, _ := utils.ConvertToPixels(self.Style["word-spacing"], self.EM, parent.Width)
444	lineHeight, _ := utils.ConvertToPixels(self.Style["line-height"], self.EM, parent.Width)
445	if lineHeight == 0 {
446		lineHeight = self.EM + 3
447	}
448
449	text.LineHeight = int(lineHeight)
450	text.WordSpacing = int(wordSpacing)
451	text.LetterSpacing = int(letterSpacing)
452	wb := " "
453
454	if self.Style["word-wrap"] == "break-word" {
455		wb = ""
456	}
457
458	if self.Style["text-wrap"] == "wrap" || self.Style["text-wrap"] == "balance" {
459		wb = ""
460	}
461
462	var dt float32
463
464	if self.Style["text-decoration-thickness"] == "auto" || self.Style["text-decoration-thickness"] == "" {
465		dt = self.EM / 7
466	} else {
467		dt, _ = utils.ConvertToPixels(self.Style["text-decoration-thickness"], self.EM, parent.Width)
468	}
469
470	col := color.Parse(self.Style, "font")
471
472	self.Color = col
473
474	text.Color = col
475	text.DecorationColor = color.Parse(self.Style, "decoration")
476	text.Align = self.Style["text-align"]
477	text.WordBreak = wb
478	text.WordSpacing = int(wordSpacing)
479	text.LetterSpacing = int(letterSpacing)
480	text.WhiteSpace = self.Style["white-space"]
481	text.DecorationThickness = int(dt)
482	text.Overlined = self.Style["text-decoration"] == "overline"
483	text.Underlined = self.Style["text-decoration"] == "underline"
484	text.LineThrough = self.Style["text-decoration"] == "linethrough"
485	text.EM = int(self.EM)
486	text.Width = int(parent.Width)
487	text.Text = n.InnerText
488
489	if self.Style["word-spacing"] == "" {
490		text.WordSpacing = font.MeasureSpace(&text)
491	}
492
493	img, width := font.Render(&text)
494	self.Texture = img
495
496	if self.Style["height"] == "" {
497		self.Height = float32(text.LineHeight)
498	}
499
500	if self.Style["width"] == "" {
501		self.Width = float32(width)
502	}
503
504	return self
505}