Added Swipe to follow nearest link/to jump to latest bookmark (#3207)

frontend/apps/reader/modules/readerlink.lua

@@ -71,6 +71,14 @@ local function isSwipeToFollowFirstLinkEnabled()
     return G_reader_settings:readSetting("swipe_to_follow_first_link") == true
 end
 
+local function isSwipeToFollowNearestLinkEnabled()
+    return G_reader_settings:readSetting("swipe_to_follow_nearest_link") == true
+end
+
+local function isSwipeToJumpToLatestBookmarkEnabled()
+    return G_reader_settings:readSetting("swipe_to_jump_to_latest_bookmark") == true
+end
+
 function ReaderLink:addToMainMenu(menu_items)
     -- insert table to main reader menu
     menu_items.follow_links = {
@@ -101,11 +109,34 @@ function ReaderLink:addToMainMenu(menu_items)
                 end,
             },
             {
-                text = _("Swipe to follow first link"),
+                text = _("Swipe to follow first link on page"),
                 checked_func = isSwipeToFollowFirstLinkEnabled,
                 callback = function()
                     G_reader_settings:saveSetting("swipe_to_follow_first_link",
                         not isSwipeToFollowFirstLinkEnabled())
+                    if isSwipeToFollowFirstLinkEnabled() then
+                        G_reader_settings:delSetting("swipe_to_follow_nearest_link") -- can't have both
+                    end
+                end,
+            },
+            {
+                text = _("Swipe to follow nearest link"),
+                checked_func = isSwipeToFollowNearestLinkEnabled,
+                callback = function()
+                    G_reader_settings:saveSetting("swipe_to_follow_nearest_link",
+                        not isSwipeToFollowNearestLinkEnabled())
+                    if isSwipeToFollowNearestLinkEnabled() then
+                        G_reader_settings:delSetting("swipe_to_follow_first_link") -- can't have both
+                    end
+                end,
+                separator = true,
+            },
+            {
+                text = _("Swipe to jump to latest bookmark"),
+                checked_func = isSwipeToJumpToLatestBookmarkEnabled,
+                callback = function()
+                    G_reader_settings:saveSetting("swipe_to_jump_to_latest_bookmark",
+                        not isSwipeToJumpToLatestBookmarkEnabled())
                 end,
             },
         }
@@ -239,15 +270,24 @@ function ReaderLink:onSwipe(_, ges)
             return self:onGoBackLink()
         end
     elseif ges.direction == "west" then
+        local ret = false
         if isSwipeToFollowFirstLinkEnabled() then
-            return self:onGoToFirstLink(ges)
+            ret = self:onGoToPageLink(ges, true)
+        elseif isSwipeToFollowNearestLinkEnabled() then
+            ret = self:onGoToPageLink(ges)
         end
+        -- If no link found, or no follow link option enabled,
+        -- jump to latest bookmark (if enabled)
+        if not ret and isSwipeToJumpToLatestBookmarkEnabled() then
+            ret = self:onGoToLatestBookmark(ges)
+        end
+        return ret
     end
 end
 
---- Goes to first link on page.
-function ReaderLink:onGoToFirstLink(ges)
-    local firstlink = nil
+--- Goes to link nearest to the gesture (or first link in page)
+function ReaderLink:onGoToPageLink(ges, use_page_first_link)
+    local selected_link = nil
     if self.ui.document.info.has_pages then
         local pos = self.view:screenToPageTransform(ges.pos)
         if not pos then
@@ -268,16 +308,28 @@ function ReaderLink:onGoToFirstLink(ges)
         --         ["x0"] = 97,
         --         ["page"] = 347
         --     },
-        -- Links may not be in the order they are in the page, so let's
-        -- find the one with the smallest y0.
+        local pos_x, pos_y = ges.pos.x, ges.pos.y
+        local shortest_dist = nil
         local first_y0 = nil
         for _, link in ipairs(links) do
             if link["page"] then
-                if first_y0 == nil or link["y0"] < first_y0 then
-                    -- onGotoLink()'s GotoPage event needs the link
-                    -- itself, and will use its "page" value
-                    firstlink = link
-                    first_y0 = link["y0"]
+                if use_page_first_link then
+                    -- Links may not be in the order they are in the page, so let's
+                    -- find the one with the smallest y0.
+                    if first_y0 == nil or link["y0"] < first_y0 then
+                        selected_link = link
+                        first_y0 = link["y0"]
+                    end
+                else
+                    local start_dist = math.pow(link.x0 - pos_x, 2) + math.pow(link.y0 - pos_y, 2)
+                    local end_dist = math.pow(link.x1 - pos_x, 2) + math.pow(link.y1 - pos_y, 2)
+                    local min_dist = math.min(start_dist, end_dist)
+                    if shortest_dist == nil or min_dist < shortest_dist then
+                        -- onGotoLink()'s GotoPage event needs the link
+                        -- itself, and will use its "page" value
+                        selected_link = link
+                        shortest_dist = min_dist
+                    end
                 end
             end
         end
@@ -304,16 +356,28 @@ function ReaderLink:onGoToFirstLink(ges)
         --         ["start_x"] = 352,
         --         ["start_y"] = 1201
         --     },
-        -- links may not be in the order they are in the page, so let's
-        -- find the one with the smallest start_y.
+        local pos_x, pos_y = ges.pos.x, ges.pos.y
+        local shortest_dist = nil
         local first_start_y = nil
         for _, link in ipairs(links) do
             if link["section"] then
-                if first_start_y == nil or link["start_y"] < first_start_y then
-                    -- onGotoLink()'s GotoXPointer event needs
-                    -- the "section" value
-                    firstlink = link["section"]
-                    first_start_y = link["start_y"]
+                if use_page_first_link then
+                    -- links may not be in the order they are in the page, so let's
+                    -- find the one with the smallest start_y.
+                    if first_start_y == nil or link["start_y"] < first_start_y then
+                        selected_link = link["section"]
+                        first_start_y = link["start_y"]
+                    end
+                else
+                    local start_dist = math.pow(link.start_x - pos_x, 2) + math.pow(link.start_y - pos_y, 2)
+                    local end_dist = math.pow(link.end_x - pos_x, 2) + math.pow(link.end_y - pos_y, 2)
+                    local min_dist = math.min(start_dist, end_dist)
+                    if shortest_dist == nil or min_dist < shortest_dist then
+                        -- onGotoLink()'s GotoXPointer event needs
+                        -- the "section" value
+                        selected_link = link["section"]
+                        shortest_dist = min_dist
+                    end
                 end
             end
         end
@@ -323,8 +387,27 @@ function ReaderLink:onGoToFirstLink(ges)
         -- So let's clear them now.
         self.ui.document:clearSelection()
     end
-    if firstlink then
-        return self:onGotoLink(firstlink)
+    if selected_link then
+        return self:onGotoLink(selected_link)
+    end
+end
+
+function ReaderLink:onGoToLatestBookmark(ges)
+    local latest_bookmark = self.ui.bookmark:getLatestBookmark()
+    if latest_bookmark then
+        if self.ui.document.info.has_pages then
+            -- self:onGotoLink() needs something with a page attribute.
+            -- we need to substract 1 to bookmark page, as links start from 0
+            -- and onGotoLink will add 1 - we need a fake_link (with a single
+            -- page attribute) so we don't touch the bookmark itself
+            local fake_link = {}
+            fake_link.page = latest_bookmark.page - 1
+            return self:onGotoLink(fake_link)
+        else
+            -- self:onGotoLink() needs a xpointer, that we find
+            -- as the bookmark page attribute
+            return self:onGotoLink(latest_bookmark.page)
+        end
     end
 end