ContentAdapter: use intermediate rendering blocks
Rendering one view per line is looking for trouble when considering preformatted blocks and possibly list/blockquotes: you want to group actions and styles together. Specifically, make preformatted blocks horizontally scrollable. This commit adds an intermediate level for rendering which produces such blocks.
This commit is contained in:
parent
685d60a09b
commit
4f41d6fecd
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@ -10,31 +10,106 @@ import android.view.ViewGroup
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import androidx.recyclerview.widget.RecyclerView
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import dev.lowrespalmtree.comet.databinding.*
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class ContentAdapter(private var content: List<Line>, private val listener: ContentAdapterListen) :
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/**
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* Adapter for a rendered Gemtext page.
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*
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* Considering each content line as a different block/View to render works until you want to render
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* preformatted lines as a whole block. This adapter approaches this issue by mapping each line to
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* a block, where most of the time it will be a 1-to-1 relation, but for blocks and possibly quotes
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* it could be a n-to-1 relation: many lines belong to the same block. This of course changes a bit
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* the way we have to render things.
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*/
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class ContentAdapter(private val listener: ContentAdapterListen) :
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RecyclerView.Adapter<ContentAdapter.ContentViewHolder>() {
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private var lastLineCount = 0
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private var lines = listOf<Line>()
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private var currentLine = 0
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private var blocks = mutableListOf<ContentBlock>()
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private var lastBlockCount = 0
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interface ContentAdapterListen {
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fun onLinkClick(url: String)
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}
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override fun getItemViewType(position: Int): Int =
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when (content[position]) {
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is EmptyLine -> TYPE_EMPTY
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is ParagraphLine -> TYPE_PARAGRAPH
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is LinkLine -> TYPE_LINK
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is PreFenceLine -> TYPE_PRE_FENCE
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is PreTextLine -> TYPE_PRE_TEXT
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is BlockquoteLine -> TYPE_BLOCKQUOTE
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is ListItemLine -> TYPE_LIST_ITEM
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is TitleLine -> when ((content[position] as TitleLine).level) {
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1 -> TYPE_TITLE_1
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2 -> TYPE_TITLE_2
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3 -> TYPE_TITLE_3
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else -> error("invalid title level")
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sealed class ContentBlock {
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object Empty : ContentBlock()
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class Paragraph(val text: String) : ContentBlock()
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class Title(val text: String, val level: Int) : ContentBlock()
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class Link(val url: String, val label: String) : ContentBlock()
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class Pre(val caption: String, var content: String, var closed: Boolean) : ContentBlock()
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class Blockquote(val text: String) : ContentBlock()
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class ListItem(val text: String) : ContentBlock()
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}
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else -> error("unknown line type")
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/** Replace the content rendered by the recycler. */
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@SuppressLint("NotifyDataSetChanged")
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fun setLines(newLines: List<Line>) {
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lines = newLines.toList() // Shallow copy to avoid concurrent update issues.
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if (lines.isEmpty()) {
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Log.d(TAG, "setLines: empty content")
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currentLine = 0
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blocks = mutableListOf()
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lastBlockCount = 0
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notifyDataSetChanged()
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} else {
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while (currentLine < lines.size) {
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when (val line = lines[currentLine]) {
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is EmptyLine -> blocks.add(ContentBlock.Empty)
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is ParagraphLine -> blocks.add(ContentBlock.Paragraph(line.text))
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is LinkLine -> blocks.add(ContentBlock.Link(line.url, line.label))
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is BlockquoteLine -> blocks.add(ContentBlock.Blockquote(line.text))
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is ListItemLine -> blocks.add(ContentBlock.ListItem(line.text))
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is TitleLine -> blocks.add(ContentBlock.Title(line.text, line.level))
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is PreFenceLine -> {
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var justClosedBlock = false
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if (blocks.isNotEmpty()) {
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val lastBlock = blocks.last()
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if (lastBlock is ContentBlock.Pre && !lastBlock.closed) {
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lastBlock.closed = true
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justClosedBlock = true
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}
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}
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if (!justClosedBlock)
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blocks.add(ContentBlock.Pre(line.caption, "", false))
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}
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is PreTextLine -> {
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val lastBlock = blocks.last()
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if (lastBlock is ContentBlock.Pre && !lastBlock.closed)
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lastBlock.content += line.text + "\n"
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else
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Log.e(TAG, "setLines: unexpected preformatted line")
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}
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}
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currentLine++
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}
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val numAdded = blocks.size - lastBlockCount
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Log.d(TAG, "setContent: added $numAdded items")
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notifyItemRangeInserted(lastBlockCount, numAdded)
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}
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lastBlockCount = blocks.size
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}
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sealed class ContentViewHolder(view: View) : RecyclerView.ViewHolder(view) {
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class Empty(binding: GemtextEmptyBinding) : ContentViewHolder(binding.root)
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class Paragraph(val binding: GemtextParagraphBinding) : ContentViewHolder(binding.root)
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class Title1(val binding: GemtextTitle1Binding) : ContentViewHolder(binding.root)
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class Title2(val binding: GemtextTitle2Binding) : ContentViewHolder(binding.root)
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class Title3(val binding: GemtextTitle3Binding) : ContentViewHolder(binding.root)
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class Link(val binding: GemtextLinkBinding) : ContentViewHolder(binding.root)
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class Pre(val binding: GemtextPreformattedBinding) : ContentViewHolder(binding.root)
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class Blockquote(val binding: GemtextBlockquoteBinding) : ContentViewHolder(binding.root)
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class ListItem(val binding: GemtextListItemBinding) : ContentViewHolder(binding.root)
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}
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override fun getItemViewType(position: Int): Int =
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when (val block = blocks[position]) {
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is ContentBlock.Empty -> TYPE_EMPTY
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is ContentBlock.Paragraph -> TYPE_PARAGRAPH
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is ContentBlock.Link -> TYPE_LINK
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is ContentBlock.Blockquote -> TYPE_BLOCKQUOTE
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is ContentBlock.ListItem -> TYPE_LIST_ITEM
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is ContentBlock.Pre -> TYPE_PREFORMATTED
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is ContentBlock.Title -> block.level // ruse
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}
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override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ContentViewHolder {
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@ -46,8 +121,7 @@ class ContentAdapter(private var content: List<Line>, private val listener: Cont
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TYPE_TITLE_2 -> ContentViewHolder.Title2(GemtextTitle2Binding.inflate(it))
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TYPE_TITLE_3 -> ContentViewHolder.Title3(GemtextTitle3Binding.inflate(it))
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TYPE_LINK -> ContentViewHolder.Link(GemtextLinkBinding.inflate(it))
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TYPE_PRE_FENCE -> ContentViewHolder.PreFence(GemtextEmptyBinding.inflate(it))
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TYPE_PRE_TEXT -> ContentViewHolder.PreText(GemtextPreformattedBinding.inflate(it))
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TYPE_PREFORMATTED -> ContentViewHolder.Pre(GemtextPreformattedBinding.inflate(it))
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TYPE_BLOCKQUOTE -> ContentViewHolder.Blockquote(GemtextBlockquoteBinding.inflate(it))
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TYPE_LIST_ITEM -> ContentViewHolder.ListItem(GemtextListItemBinding.inflate(it))
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else -> error("invalid view type")
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@ -57,80 +131,45 @@ class ContentAdapter(private var content: List<Line>, private val listener: Cont
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@SuppressLint("SetTextI18n")
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override fun onBindViewHolder(holder: ContentViewHolder, position: Int) {
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val line = content[position]
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when (holder) {
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is ContentViewHolder.Paragraph ->
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holder.binding.textView.text = (line as ParagraphLine).text
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is ContentViewHolder.Title1 -> holder.binding.textView.text = (line as TitleLine).text
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is ContentViewHolder.Title2 -> holder.binding.textView.text = (line as TitleLine).text
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is ContentViewHolder.Title3 -> holder.binding.textView.text = (line as TitleLine).text
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is ContentViewHolder.Link -> {
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val text = if ((line as LinkLine).label.isNotEmpty()) line.label else line.url
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val underlined = SpannableString(text)
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underlined.setSpan(UnderlineSpan(), 0, underlined.length, 0)
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holder.binding.textView.text = underlined
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holder.binding.root.setOnClickListener { listener.onLinkClick(line.url) }
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when (val block = blocks[position]) {
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is ContentBlock.Empty -> {}
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is ContentBlock.Paragraph ->
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(holder as ContentViewHolder.Paragraph).binding.textView.text = block.text
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is ContentBlock.Blockquote ->
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(holder as ContentViewHolder.Blockquote).binding.textView.text = block.text
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is ContentBlock.ListItem ->
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(holder as ContentViewHolder.ListItem).binding.textView.text = "\u25CF ${block.text}"
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is ContentBlock.Title -> {
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when (block.level) {
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1 -> (holder as ContentViewHolder.Title1).binding.textView.text = block.text
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2 -> (holder as ContentViewHolder.Title2).binding.textView.text = block.text
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3 -> (holder as ContentViewHolder.Title3).binding.textView.text = block.text
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}
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is ContentViewHolder.PreText ->
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holder.binding.textView.text = (line as PreTextLine).text
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is ContentViewHolder.Blockquote ->
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holder.binding.textView.text = (line as BlockquoteLine).text
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is ContentViewHolder.ListItem ->
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holder.binding.textView.text = "\u25CF ${(line as ListItemLine).text}"
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else -> {}
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}
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is ContentBlock.Link -> {
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val label = if (block.label.isNotBlank()) block.label else block.url
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val underlinedLabel = SpannableString(label)
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underlinedLabel.setSpan(UnderlineSpan(), 0, underlinedLabel.length, 0)
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(holder as ContentViewHolder.Link).binding.textView.text = underlinedLabel
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holder.binding.root.setOnClickListener { listener.onLinkClick(block.url) }
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}
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is ContentBlock.Pre ->
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(holder as ContentViewHolder.Pre).binding.textView.text = block.content
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}
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}
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override fun getItemCount(): Int = content.size
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/**
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* Replace the content rendered by the recycler.
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*
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* The new content list may or may not be the same object as the previous one, we don't
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* assume anything. The assumptions this function do however are:
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* - If the new content is empty, we are about to load new content, so clear the recycler.
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* - If it's longer than before, we received new streamed content, so *append* data.
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* - If it's shorter or the same size than before, we do not notify anything and let the caller
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* manage the changes itself.
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*/
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@SuppressLint("NotifyDataSetChanged")
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fun setContent(newContent: List<Line>) {
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content = newContent.toList() // Shallow copy to avoid concurrent update issues.
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if (content.isEmpty()) {
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Log.d(TAG, "setContent: empty content")
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notifyDataSetChanged()
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} else if (content.size > lastLineCount) {
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val numAdded = content.size - lastLineCount
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Log.d(TAG, "setContent: added $numAdded items")
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notifyItemRangeInserted(lastLineCount, numAdded)
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}
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lastLineCount = content.size
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}
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sealed class ContentViewHolder(view: View) : RecyclerView.ViewHolder(view) {
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class Empty(val binding: GemtextEmptyBinding) : ContentViewHolder(binding.root)
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class Paragraph(val binding: GemtextParagraphBinding) : ContentViewHolder(binding.root)
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class Title1(val binding: GemtextTitle1Binding) : ContentViewHolder(binding.root)
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class Title2(val binding: GemtextTitle2Binding) : ContentViewHolder(binding.root)
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class Title3(val binding: GemtextTitle3Binding) : ContentViewHolder(binding.root)
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class Link(val binding: GemtextLinkBinding) : ContentViewHolder(binding.root)
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class PreFence(val binding: GemtextEmptyBinding) : ContentViewHolder(binding.root)
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class PreText(val binding: GemtextPreformattedBinding) : ContentViewHolder(binding.root)
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class Blockquote(val binding: GemtextBlockquoteBinding) : ContentViewHolder(binding.root)
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class ListItem(val binding: GemtextListItemBinding) : ContentViewHolder(binding.root)
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}
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override fun getItemCount(): Int = blocks.size
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companion object {
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const val TAG = "ContentRecycler"
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const val TYPE_EMPTY = 0
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const val TYPE_PARAGRAPH = 1
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const val TYPE_TITLE_1 = 2
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const val TYPE_TITLE_2 = 3
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const val TYPE_TITLE_3 = 4
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const val TYPE_TITLE_1 = 1
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const val TYPE_TITLE_2 = 2
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const val TYPE_TITLE_3 = 3
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const val TYPE_PARAGRAPH = 4
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const val TYPE_LINK = 5
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const val TYPE_PRE_FENCE = 6
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const val TYPE_PRE_TEXT = 7
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const val TYPE_BLOCKQUOTE = 8
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const val TYPE_LIST_ITEM = 9
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const val TYPE_PREFORMATTED = 6
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const val TYPE_BLOCKQUOTE = 7
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const val TYPE_LIST_ITEM = 8
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}
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}
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@ -21,6 +21,7 @@ class ListItemLine(val text: String) : Line
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const val TAG = "Gemtext"
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/** Pipe incoming gemtext data into parsed Lines. */
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fun parseData(
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inChannel: Channel<ByteArray>,
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charset: Charset,
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@ -51,19 +52,23 @@ fun parseData(
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return channel
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}
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/** Parse a single line into a Line object. */
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private fun parseLine(line: CharBuffer, isPreformatted: Boolean): Line =
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when {
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line.isEmpty() -> EmptyLine()
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line.startsWith("###") -> TitleLine(3, getCharsFrom(line, 3))
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line.startsWith("##") -> TitleLine(2, getCharsFrom(line, 2))
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line.startsWith("#") -> TitleLine(1, getCharsFrom(line, 1))
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line.startsWith(">") -> BlockquoteLine(getCharsFrom(line, 1))
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line.startsWith("```") -> PreFenceLine(getCharsFrom(line, 3))
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line.startsWith("* ") -> ListItemLine(getCharsFrom(line, 2))
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line.startsWith(">") -> getCharsFrom(line, 1) // eh empty lines in quotes…
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.run { if (isBlank()) EmptyLine() else BlockquoteLine(this) }
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line.startsWith("=>") -> getCharsFrom(line, 2)
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.split(" ", limit = 2)
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.run { LinkLine(get(0), if (size == 2) get(1).trimStart() else "") }
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else -> if (isPreformatted) PreTextLine(line.toString()) else ParagraphLine(line.toString())
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isPreformatted -> PreTextLine(line.toString())
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line.isEmpty() -> EmptyLine()
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else -> ParagraphLine(line.toString())
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}
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/** Get trimmed string from the char buffer starting from this position. */
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private fun getCharsFrom(line: CharBuffer, index: Int) = line.substring(index).trim()
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@ -39,7 +39,7 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
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setContentView(binding.root)
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pageViewModel = ViewModelProvider(this)[PageViewModel::class.java]
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adapter = ContentAdapter(listOf(), this)
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adapter = ContentAdapter(this)
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binding.contentRecycler.layoutManager = LinearLayoutManager(this)
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binding.contentRecycler.adapter = adapter
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@ -110,7 +110,7 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
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private fun updateLines(lines: List<Line>) {
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Log.d(TAG, "updateLines: ${lines.size} lines")
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adapter.setContent(lines)
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adapter.setLines(lines)
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}
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private fun handleEvent(event: PageViewModel.Event) {
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@ -147,7 +147,7 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
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try {
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startActivity(Intent(ACTION_VIEW, uri))
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} catch (e: ActivityNotFoundException) {
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alert("Can't open this URL.")
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alert("Can't find an app to open \"${uri.scheme}\" URLs.")
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}
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}
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4
app/src/main/res/drawable/devborders.xml
Normal file
4
app/src/main/res/drawable/devborders.xml
Normal file
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@ -0,0 +1,4 @@
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<?xml version="1.0" encoding="utf-8"?>
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<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
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<stroke android:width="1dip" android:color="@color/black"/>
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</shape>
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BIN
app/src/main/res/font/hack.ttf
Normal file
BIN
app/src/main/res/font/hack.ttf
Normal file
Binary file not shown.
4
app/src/main/res/font/preformatted.xml
Normal file
4
app/src/main/res/font/preformatted.xml
Normal file
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@ -0,0 +1,4 @@
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<?xml version="1.0" encoding="utf-8"?>
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<font-family xmlns:app="http://schemas.android.com/apk/res-auto">
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<font app:fontStyle="normal" app:fontWeight="400" app:font="@font/hack"/>
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</font-family>
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@ -1,5 +1,7 @@
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<?xml version="1.0" encoding="utf-8"?>
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<TextView xmlns:android="http://schemas.android.com/apk/res/android"
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android:layout_width="2dp"
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android:layout_height="1dp"
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android:backgroundTint="@color/teal_700" />
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xmlns:tools="http://schemas.android.com/tools"
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android:layout_width="0dp"
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android:layout_height="0dp"
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android:textSize="8sp"
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tools:ignore="SmallSp" />
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@ -1,13 +1,19 @@
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<?xml version="1.0" encoding="utf-8"?>
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<TextView xmlns:android="http://schemas.android.com/apk/res/android"
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<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
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android:layout_height="wrap_content"
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android:layout_width="match_parent"
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android:paddingStart="16dp"
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android:paddingEnd="16dp">
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<TextView
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android:id="@+id/text_view"
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:textSize="14sp"
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android:textColor="@color/text"
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android:fontFamily="@font/preformatted"
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android:typeface="monospace"
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android:layout_width="match_parent"
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android:layout_height="wrap_content"
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android:paddingStart="16dp"
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android:paddingEnd="8dp"
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android:paddingTop="2dp"
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android:paddingBottom="2dp"
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android:background="@color/purple_200" />
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android:paddingTop="4dp"
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android:paddingBottom="4dp" />
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</HorizontalScrollView>
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@ -6,6 +6,12 @@
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<color name="teal_200">#FF03DAC5</color>
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<color name="teal_700">#FF018786</color>
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<color name="black">#FF000000</color>
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<color name="white">#FFFFFFFF</color>
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<color name="text">#222222</color>
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<color name="bright">#F3F4ED</color>
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<color name="text_light">#536162</color>
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<color name="text">#424642</color>
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<color name="orange">#C06014</color>
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<color name="orange_dark">#683C19</color>
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<color name="teal">#14C0B2</color>
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<color name="teal_dark">#147169</color>
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</resources>
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@ -7,5 +7,6 @@
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<item name="android:paddingEnd">16dp</item>
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<item name="android:paddingTop">2dp</item>
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<item name="android:paddingBottom">4dp</item>
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<item name="android:textIsSelectable">true</item>
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</style>
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</resources>
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@ -2,15 +2,17 @@
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<!-- Base application theme. -->
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<style name="Theme.Comet" parent="Theme.MaterialComponents.DayNight.NoActionBar">
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<!-- Primary brand color. -->
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<item name="colorPrimary">@color/purple_200</item>
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<item name="colorPrimaryVariant">@color/purple_500</item>
|
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<item name="colorOnPrimary">@color/white</item>
|
||||
<item name="colorPrimary">@color/orange</item>
|
||||
<item name="colorPrimaryVariant">@color/orange_dark</item>
|
||||
<item name="colorOnPrimary">@color/bright</item>
|
||||
<!-- Secondary brand color. -->
|
||||
<item name="colorSecondary">@color/teal_200</item>
|
||||
<item name="colorSecondaryVariant">@color/teal_700</item>
|
||||
<item name="colorOnSecondary">@color/black</item>
|
||||
<item name="colorSecondary">@color/teal</item>
|
||||
<item name="colorSecondaryVariant">@color/teal_dark</item>
|
||||
<item name="colorOnSecondary">@color/text</item>
|
||||
<!-- Status bar color. -->
|
||||
<item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
|
||||
<!-- Customize your theme here. -->
|
||||
<item name="android:windowBackground">@color/bright</item>
|
||||
<item name="android:progressBackgroundTint">?attr/colorSecondaryVariant</item>
|
||||
</style>
|
||||
</resources>
|
||||
Reference in a new issue