Pagination View

src/utils.py

@@ -3,8 +3,10 @@
 import aiohttp
 import logging
 import async_timeout
+from typing import Callable
 
-from discord import Interaction, Embed, Colour
+from discord import Interaction, Embed, Colour, ButtonStyle, Button
+from discord.ui import View, button
 
 log = logging.getLogger(__name__)
 
@@ -53,6 +55,111 @@ class FollowupIcons:
     assigned = "https://img.icons8.com/fluency-systems-filled/48/4598DA/hashtag-large.png"
 
 
+class PaginationView(View):
+    def __init__(
+        self, inter: Interaction, embed: Embed, getdata: Callable,
+        formatdata: Callable, maxpage: int, initpage: int=1
+    ):
+        self.inter = inter
+        self.embed = embed
+        self.getdata = getdata
+        self.formatdata = formatdata
+        self.maxpage = maxpage
+        self.index = initpage
+        super().__init__(timeout=100)
+
+    async def check_user_is_author(self, inter: Interaction) -> bool:
+        """Ensure the user is the author of the original command."""
+
+        if inter.user == self.inter.user:
+            return True
+
+        await inter.response.defer()
+        await (
+            Followup(None, "Only the author can interact with this.")
+            .error()
+            .send(inter, ephemeral=True)
+        )
+        return False
+
+    async def on_timeout(self):
+        """Erase the controls on timeout."""
+
+        message = await self.inter.original_response()
+        await message.edit(view=None)
+
+    @staticmethod
+    def calc_total_pages(results: int, max_pagesize: int) -> int:
+        result = ((results - 1) // max_pagesize) + 1
+        log.debug("total pages calculated: %s", result)
+        return result
+
+    @button(emoji="◀️", style=ButtonStyle.blurple)
+    async def backward(self, inter: Interaction, button: Button):
+        self.index -= 1
+        await inter.response.defer()
+        self.inter = inter
+        await self.navigate()
+
+    @button(emoji="▶️", style=ButtonStyle.blurple)
+    async def forward(self, inter: Interaction, button: Button):
+        self.index += 1
+        await inter.response.defer()
+        self.inter = inter
+        await self.navigate()
+
+    @button(emoji="⏭️", style=ButtonStyle.blurple)
+    async def start_or_end(self, inter: Interaction, button: Button):
+        if self.index  <= self.maxpage // 2:
+            self.index = self.maxpage
+        else:
+            self.index = 1
+
+        await inter.response.defer()
+        self.inter = inter
+        await self.navigate()
+
+    async def navigate(self):
+        log.debug("navigating to page: %s", self.index)
+
+        self.update_buttons()
+        paged_embed = await self.create_paged_embed()
+        await self.inter.edit_original_response(embed=paged_embed, view=self)
+
+    async def create_paged_embed(self) -> Embed:
+        embed = self.embed.copy()
+        data = await self.getdata(self.index)
+
+        for item in data:
+            key, value = self.formatdata(item)
+            embed.add_field(name=key, value=value, inline=False)
+
+        if self.maxpage != 1:
+            embed.set_footer(text=f"Page {self.index}/{self.maxpage}")
+
+        return embed
+
+    def update_buttons(self):
+        if self.index >= self.maxpage:
+            self.children[2].emoji = "⏮️"
+        else:
+            self.children[2].emoji = "⏭️"
+
+        self.children[0].disabled = self.index == 1
+        self.children[1].disabled = self.index == self.maxpage
+
+    async def send(self):
+        embed = await self.create_paged_embed()
+
+        if self.maxpage == 1:
+            await self.inter.edit_original_response(embed=embed)
+            return
+
+        self.update_buttons()
+        await self.inter.edit_original_response(embed=embed, view=self)
+
+
+
 class Followup:
     """Wrapper for a discord embed to follow up an interaction."""
 
@@ -66,10 +173,10 @@ class Followup:
             description=description
         )
 
-    async def send(self, inter: Interaction, message: str = None):
+    async def send(self, inter: Interaction, message: str = None, ephemeral: bool = False):
         """"""
 
-        await inter.followup.send(content=message, embed=self._embed)
+        await inter.followup.send(content=message, embed=self._embed, ephemeral=ephemeral)
 
     def fields(self, inline: bool = False, **fields: dict):
         """"""
@@ -86,6 +193,13 @@ class Followup:
 
         return self
 
+    def footer(self, text: str, icon_url: str = None):
+        """"""
+
+        self._embed.set_footer(text=text, icon_url=icon_url)
+
+        return self
+
     def error(self):
         """"""