Release v0.6.5: preserve caption links and connect arrows to other objects

README.md

@@ -101,6 +101,13 @@ change its diameter. Wheel up increases the size; wheel down decreases it. These
 and update linked arrows. **Ctrl+D** clones the selected object with a small offset. A cloned number
 gets the smallest available positive number, just like a newly placed number: gaps left by deletion
 are filled first, without renumbering existing objects. A cloned arrow keeps its style but starts without endpoint links.
+Arrow and line endpoints can attach to numbered markers, rectangles, circles, ellipses, text blocks,
+and other arrows or strokes. Drop an endpoint onto the target; use **Ctrl+drag** to start a new
+connector over an existing object. Attached endpoints follow movement and resizing; text attachments
+also follow rotation. Arrow-to-arrow attachments retain their relative position along the target line.
+Clicking a connector or adding/editing its caption preserves its links. Moving the whole connector
+intentionally detaches its endpoints; moving one endpoint detaches only that end. Deleting a target
+leaves connected endpoints at their last position. Self-links and circular dependency chains are rejected.
 The compact toolbar uses [Lucide](https://lucide.dev) icons with hover tooltips showing each action
 and its keyboard shortcut.
 Drop either arrow endpoint onto a number to link it to the circle's edge. Linked endpoints follow

Release/README.md

@@ -1,17 +1,18 @@
 # Latest Windows release
 
-## v0.6.3 — 2026-10-29
+## v0.6.5 — 2026-10-29
 
-- Hide the fullscreen capture selection before submitting a notification when automatic editor opening is disabled. Previously the selection remained visible during submission, which could suppress the banner under Windows fullscreen notification rules.
-- Default to capture → notification → click → editor. **Open editor after screen capture** is now off by default; explicitly saved preferences are preserved.
-- Retain the editor fallback for immediate notification errors.
-- Check for updates in the background every 6 hours after the startup check. Notify once per version per session, retry after network failures at the next interval, and install only after confirmation.
+## Changes
+- Preserve endpoint links when selecting a connector or adding/editing its caption through double-click, F2 or the caption button. A click without movement no longer detaches the connector.
+- Attach arrow and line endpoints to rectangles, circles, ellipses, text blocks, other arrows/lines, and freehand/highlight strokes, in addition to numbered markers.
+- Keep attachments aligned as targets move or resize; text attachments also follow rotation. Arrow-to-arrow chains resolve in dependency order.
+- Preserve links through Undo/Redo. Deleted targets leave endpoints at their last position; clones start without links. Self-links and circular dependencies are rejected.
 
-Verified: 176 native checks, 403 input/layout checks at 240 DPI, screenshot editor UI integration,
-isolated notification registration checks, and 45 updater checks. The new UI regression test failed
-before the fix and passes afterward: the selection is hidden at notification submission.
-Banner behavior still needs confirmation on the affected laptop. Windows Do Not Disturb can
-send notifications directly to the notification center; asynchronous toast failures are not yet monitored.
+## Usage
+Drop a connector endpoint onto the target. Use **Ctrl+drag** to start a new connector over an existing object. Moving a whole connector detaches both of its endpoints; dragging one endpoint detaches only that end.
+
+## Validation
+176 native checks, 440 input/layout checks at 240 DPI, screenshot editor UI integration, isolated notification registration, and 45 updater checks. Coverage includes caption editing, shape-arrow-arrow chains, movement, resize, text rotation, deletion, cloning, cycle rejection, and Undo/Redo.
 
 **Upgrade:** choose Update in the tray menu. Legacy v0.3.0–v0.4.1 clients first receive the
 v0.4.2 compatibility bridge, then the current full release. v0.2.3 and earlier require manual installation.

Release/SHA256SUMS.txt

@@ -1 +1 @@
-a43786b06878da0f069dbad0fa29587a736dd2d8904c7bc991f5cf0c0570a16f  KSwitcher-win-x64.zip
+bea45fdb33657fdfd5b065cdf10a3c358febdd5e895672dd106ec5ef2dd16c9a  KSwitcher-win-x64.zip

resources/app.rc

@@ -9,8 +9,8 @@ IDC_SCREENSHOT_PENCIL CURSOR "icons/lucide/pencil.cur"
 1 RT_MANIFEST "app.manifest"
 201 RCDATA "update.ps1"
 1 VERSIONINFO
- FILEVERSION 0,6,3,0
- PRODUCTVERSION 0,6,3,0
+ FILEVERSION 0,6,5,0
+ PRODUCTVERSION 0,6,5,0
  FILEOS VOS_NT_WINDOWS32
  FILETYPE VFT_APP
 BEGIN
@@ -20,7 +20,7 @@ BEGIN
   BEGIN
    VALUE "FileDescription", "KSwitcher — native keyboard and clipboard utility"
    VALUE "ProductName", "KSwitcher"
-   VALUE "FileVersion", "0.6.3"
+   VALUE "FileVersion", "0.6.5"
   END
  END
  BLOCK "VarFileInfo"

src/screenshot.cpp

@@ -3,6 +3,8 @@
 #include "../resources/resource.h"
 #include <algorithm>
 #include <cmath>
+#include <functional>
+#include <unordered_set>
 #include <windowsx.h>
 #include <commctrl.h>
 #include <commdlg.h>
@@ -197,7 +199,7 @@ void updateStatus(Capture &c)
     else if(part==MarkPart::Rotation) text=L"Drag to rotate text | Hold Shift for 15-degree steps";
     else if(part==MarkPart::Thickness) text=L"Drag to change thickness | Mouse wheel over object = size";
     else if(part==MarkPart::Radius) text=L"Drag to resize the number | Mouse wheel = diameter";
-    else if(part==MarkPart::Start || part==MarkPart::End) text=L"Drag handle to resize | Arrow endpoints can snap to numbered markers";
+    else if(part==MarkPart::Start || part==MarkPart::End) text=L"Drag handle to resize | Endpoints can snap to objects and other arrows";
     else if(c.selected>=0) {
         const auto &m=c.marks[c.selected];
         if(c.selectedLabel || part==MarkPart::Label)
@@ -274,6 +276,7 @@ void finishInlineText(HWND w,Capture &c,bool commit)
         }
         if(!empty) c.textDefaults=c.textDraft;
     }
+    if(commit) resolveScreenshotLinks(c.marks);
     c.textIndex=-1; c.editingLabel=false;
     InvalidateRect(w,nullptr,FALSE);
 }
@@ -575,6 +578,15 @@ std::pair<int,MarkPart> markAt(Capture &c, POINT p)
 {
     if((c.arrow || c.highlight || c.freehand || c.textTool) && (GetKeyState(VK_CONTROL)&0x8000)) return {-1,MarkPart::None};
     double tolerance=double(std::max(6,c.unit/6))*c.image->width/std::max(1L,c.view.right-c.view.left);
+    // Badges are painted above connectors. Their visible bodies must also win
+    // hit testing, even when an attached connector is currently selected.
+    for(int i=int(c.marks.size())-1;i>=0;--i) {
+        const auto &m=c.marks[i];
+        if(m.number && std::hypot(double(p.x-m.from.x),double(p.y-m.from.y))<=m.radius) {
+            auto part=hitScreenshotMark(m,p,tolerance);
+            return {i,part};
+        }
+    }
     if(c.selected>=0)
     {
         const auto &m=c.marks[c.selected];
@@ -883,6 +895,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     if(chooseTextFont(w,draft)) {
                         c->remember(c->marks); c->marks[c->selected]=draft;
                         c->textDefaults=draft.isLine()?screenshotArrowLabel(draft):draft;
+                        resolveScreenshotLinks(c->marks);
                     }
                 } else chooseTextFont(w,c->textDefaults);
                 SetFocus(w); InvalidateRect(w,nullptr,FALSE); return 0;
@@ -936,7 +949,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 auto &mark=c->marks[c->selected];
                 int &value=mark.isText()?mark.fontSize:mark.thickness;
                 int next=std::clamp(value+(LOWORD(wp)==16?1:-1),mark.isText()?6:mark.isHighlight()?4:1,mark.isText()?200:mark.isHighlight()?100:30);
-                if(next!=value) { c->remember(c->marks); value=next; }
+                if(next!=value) { c->remember(c->marks); value=next; resolveScreenshotLinks(c->marks); }
             }
             if (LOWORD(wp)==13) { copy(w,*c); return 0; }
             if (LOWORD(wp)==12 || LOWORD(wp)==18)
@@ -1126,7 +1139,8 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     if (!c->editing) { finishSelection(w,*c); return 0; }
                     else if(c->part!=MarkPart::None)
                     {
-                        if(c->part==MarkPart::Start || c->part==MarkPart::End)
+                        if((c->part==MarkPart::Start || c->part==MarkPart::End) &&
+                           (c->start.x!=c->end.x || c->start.y!=c->end.y))
                         {
                             auto &mark=c->marks[c->selected];
                             linkScreenshotEndpoint(mark,c->part==MarkPart::Start,c->end,c->marks,6);
@@ -1353,27 +1367,107 @@ ScreenshotMark cloneScreenshotMark(const ScreenshotMark &original,const std::vec
 {
     auto result=original;
     result.fromNumber=result.toNumber=0;
+    result.id=0; result.fromLink={}; result.toLink={};
     if(result.number) result.number=nextScreenshotNumber(marks);
     auto bounds=markBounds(result);
     LONG dx=bounds.right+16<width?16:-16;
     LONG dy=bounds.bottom+16<height?16:-16;
     return dragScreenshotMark(result,MarkPart::Body,{0,0},{dx,dy},width,height);
 }
+namespace {
+void assignMarkIds(std::vector<ScreenshotMark> &marks)
+{
+    static unsigned long long next=1;
+    for(const auto &m:marks) next=std::max(next,m.id+1);
+    std::unordered_set<unsigned long long> used;
+    for(auto &m:marks) {
+        if(!m.id || !used.insert(m.id).second) { m.id=next++; used.insert(m.id); }
+    }
+}
+POINT objectAnchor(const ScreenshotMark &m,const ScreenshotLink &link)
+{
+    if(m.isText() || m.shape!=ScreenshotShape::None) {
+        auto r=m.isText()?plainTextBounds(m):region(m.from,m.to);
+        POINT p{LONG(std::lround(r.left+(r.right-r.left)*link.u)),LONG(std::lround(r.top+(r.bottom-r.top)*link.v))};
+        return m.isText()?rotateTextPoint(m,p):p;
+    }
+    size_t segments=m.points.size()>1?m.points.size()-1:1;
+    double along=std::clamp(link.u,0.0,1.0)*segments;
+    size_t i=std::min(size_t(along),segments-1); double t=along-i;
+    POINT a=m.points.size()>1?m.points[i]:m.from,b=m.points.size()>1?m.points[i+1]:m.to;
+    return {LONG(std::lround(a.x+(b.x-a.x)*t)),LONG(std::lround(a.y+(b.y-a.y)*t))};
+}
+bool findObjectAnchor(const ScreenshotMark &m,POINT drop,double tolerance,ScreenshotLink &link)
+{
+    link={m.id,0,0};
+    if(m.isText() || m.shape!=ScreenshotShape::None) {
+        auto r=m.isText()?plainTextBounds(m):region(m.from,m.to);
+        POINT p=m.isText()?rotateTextPoint(m,drop,-1):drop;
+        double w=std::max(1L,r.right-r.left),h=std::max(1L,r.bottom-r.top);
+        double x=(p.x-r.left)/w,y=(p.y-r.top)/h;
+        bool inside=x>=0 && x<=1 && y>=0 && y<=1;
+        if(m.shape==ScreenshotShape::Circle || m.shape==ScreenshotShape::Ellipse) {
+            double dx=2*x-1,dy=2*y-1,length=std::hypot(dx,dy);
+            inside=length<=1;
+            if(length<0.001) { dx=1; dy=0; length=1; }
+            link.u=(1+dx/length)/2; link.v=(1+dy/length)/2;
+        } else {
+            link.u=std::clamp(x,0.0,1.0); link.v=std::clamp(y,0.0,1.0);
+            if(inside) {
+                double edges[]{x*w,(1-x)*w,y*h,(1-y)*h};
+                auto side=std::min_element(edges,edges+4)-edges;
+                if(side<2) link.u=side==0?0:1; else link.v=side==2?0:1;
+            }
+        }
+        auto anchor=objectAnchor(m,link);
+        return inside || std::hypot(double(drop.x-anchor.x),double(drop.y-anchor.y))<=tolerance;
+    }
+    double best=1e100;
+    size_t segments=m.points.size()>1?m.points.size()-1:1;
+    for(size_t i=0;i<segments;++i) {
+        POINT a=m.points.size()>1?m.points[i]:m.from,b=m.points.size()>1?m.points[i+1]:m.to;
+        double dx=b.x-a.x,dy=b.y-a.y,length=dx*dx+dy*dy;
+        double t=length?std::clamp(((drop.x-a.x)*dx+(drop.y-a.y)*dy)/length,0.0,1.0):0;
+        double distance=std::hypot(drop.x-a.x-t*dx,drop.y-a.y-t*dy);
+        if(distance<best) { best=distance; link.u=(i+t)/segments; }
+    }
+    return best<=tolerance+m.thickness/2.0;
+}
+}
 void linkScreenshotEndpoint(ScreenshotMark &arrow, bool start, POINT drop,
-                            const std::vector<ScreenshotMark> &marks, double tolerance)
+                            std::vector<ScreenshotMark> &marks, double tolerance)
 {
-    auto &link=start?arrow.fromNumber:arrow.toNumber;
-    link=0;
-    if(arrow.shape!=ScreenshotShape::None || arrow.isText()) return;
+    assignMarkIds(marks);
+    auto &number=start?arrow.fromNumber:arrow.toNumber;
+    auto &link=start?arrow.fromLink:arrow.toLink;
+    number=0; link={};
+    if(!arrow.isLine()) return;
+    // Number badges are drawn above other objects.
     for(auto it=marks.rbegin();it!=marks.rend();++it)
-        if(it->number && std::hypot(double(drop.x-it->from.x),double(drop.y-it->from.y))<=it->radius+tolerance)
-        {
-            link=it->number;
-            break;
+        if(it->number && std::hypot(double(drop.x-it->from.x),double(drop.y-it->from.y))<=it->radius+tolerance) {
+            number=it->number; return;
+        }
+    auto wouldCycle=[&](unsigned long long id) {
+        std::vector<unsigned long long> pending{id}; std::unordered_set<unsigned long long> seen;
+        while(!pending.empty()) {
+            auto current=pending.back(); pending.pop_back();
+            if(arrow.id && current==arrow.id) return true;
+            if(!current || !seen.insert(current).second) continue;
+            for(const auto &m:marks) if(m.id==current) {
+                pending.push_back(m.fromLink.target); pending.push_back(m.toLink.target); break;
+            }
+        }
+        return false;
+    };
+    for(auto it=marks.rbegin();it!=marks.rend();++it) {
+        if(it->number || &*it==&arrow || (arrow.id && it->id==arrow.id)) continue;
+        ScreenshotLink candidate;
+        if(findObjectAnchor(*it,drop,tolerance,candidate) && !wouldCycle(it->id)) { link=candidate; return; }
     }
 }
 void resolveScreenshotLinks(std::vector<ScreenshotMark> &marks)
 {
+    assignMarkIds(marks);
     auto badge=[&](int number) -> const ScreenshotMark * {
         if(number) for(const auto &m:marks) if(m.number==number) return &m;
         return nullptr;
@@ -1383,9 +1477,21 @@ void resolveScreenshotLinks(std::vector<ScreenshotMark> &marks)
         if(length<0.001) { dx=start?1:-1; dy=0; length=1; }
         return {m.from.x+LONG(std::lround(m.radius*dx/length)),m.from.y+LONG(std::lround(m.radius*dy/length))};
     };
-    for(auto &m:marks)
-    {
-        if(m.number || m.isHighlight() || m.isText() || m.shape!=ScreenshotShape::None) continue;
+    std::vector<int> state(marks.size());
+    std::function<void(size_t)> resolve=[&](size_t index) {
+        if(state[index]) return;
+        state[index]=1;
+        auto &m=marks[index];
+        if(m.isLine()) {
+            auto attach=[&](ScreenshotLink &link,POINT &point) {
+                if(!link.target) return;
+                for(size_t i=0;i<marks.size();++i) if(marks[i].id==link.target) {
+                    if(state[i]==1) { link={}; return; } // Reject cyclic dependencies.
+                    resolve(i); point=objectAnchor(marks[i],link); return;
+                }
+                link={}; // Deleted targets leave endpoints at their last position.
+            };
+            attach(m.fromLink,m.from); attach(m.toLink,m.to);
             auto from=badge(m.fromNumber),to=badge(m.toNumber);
             if(!from) m.fromNumber=0;
             if(!to) m.toNumber=0;
@@ -1394,6 +1500,9 @@ void resolveScreenshotLinks(std::vector<ScreenshotMark> &marks)
             if(to) m.to=rim(*to,start,false);
             if(m.freehand && !m.points.empty()) { m.points.front()=m.from; m.points.back()=m.to; }
         }
+        state[index]=2;
+    };
+    for(size_t i=0;i<marks.size();++i) resolve(i);
 }
 MarkPart hitScreenshotMark(const ScreenshotMark &m, POINT p, double tolerance)
 {
@@ -1461,6 +1570,7 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
                                   POINT position, int width, int height, bool snapRotation)
 {
     auto m=original;
+    if(position.x==origin.x && position.y==origin.y) return m;
     if(part==MarkPart::Rotation && (m.isText() || (m.isLine() && !m.label.empty()))) {
         if(position.x==origin.x && position.y==origin.y) return m;
         auto text=m.isText()?m:screenshotArrowLabel(m);
@@ -1496,6 +1606,7 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
     else if(part==MarkPart::Body)
     {
         m.fromNumber=m.toNumber=0;
+        m.fromLink={}; m.toLink={};
         auto shift=[&](LONG delta,LONG first,LONG last,int extent) {
             LONG low=-first,high=LONG(extent-1)-last;
             if(low>high && m.isText()) {
@@ -1515,6 +1626,7 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
     else if(part==MarkPart::Start || part==MarkPart::End)
     {
         (part==MarkPart::Start?m.fromNumber:m.toNumber)=0;
+        (part==MarkPart::Start?m.fromLink:m.toLink)={};
         auto &endpoint=part==MarkPart::Start?m.from:m.to;
         endpoint.x=std::clamp(endpoint.x+position.x-origin.x,0L,LONG(width-1));
         endpoint.y=std::clamp(endpoint.y+position.y-origin.y,0L,LONG(height-1));

src/screenshot.h

@@ -17,6 +17,10 @@ enum class LineStyle { Solid, Dotted, Dashed, DashDot };
 enum class LineEnds { End, Start, Both, None };
 enum class ScreenshotShape { None, Rectangle, Circle, Ellipse };
 struct ScreenshotOffset { double x, y; };
+struct ScreenshotLink {
+    unsigned long long target{};
+    double u{}, v{}; // Relative boundary position, or fractional position along a path.
+};
 struct ScreenshotMark {
     POINT from, to; int number; int radius = 15; int thickness = 3;
     int fromNumber = 0, toNumber = 0;
@@ -33,6 +37,8 @@ struct ScreenshotMark {
     std::wstring label;
     ScreenshotOffset labelOffset{0,-24}; // Along the line and perpendicular to it, in image pixels.
     bool labelRotationManual=false;
+    unsigned long long id{};
+    ScreenshotLink fromLink, toLink;
     bool isText() const { return !text.empty(); }
     bool isHighlight() const { return !points.empty() && !freehand; }
     bool isLine() const { return !number && !isText() && !isHighlight() && shape==ScreenshotShape::None; }
@@ -48,7 +54,7 @@ class ScreenshotHistory {
 };
 void resolveScreenshotLinks(std::vector<ScreenshotMark> &);
 void linkScreenshotEndpoint(ScreenshotMark &, bool start, POINT drop,
-                            const std::vector<ScreenshotMark> &, double tolerance);
+                            std::vector<ScreenshotMark> &, double tolerance);
 enum class MarkPart { None, Body, Start, End, Radius, Thickness, Rotation, Label };
 POINT screenshotThicknessHandle(const ScreenshotMark &, double clearance = 16);
 ScreenshotMark cloneScreenshotMark(const ScreenshotMark &, const std::vector<ScreenshotMark> &, int width, int height);

src/update.h

@@ -2,7 +2,7 @@
 #include "platform.h"
 namespace ks
 {
-inline constexpr wchar_t AppVersion[] = L"0.6.3";
+inline constexpr wchar_t AppVersion[] = L"0.6.5";
 inline constexpr UINT UpdateMessage = WM_APP + 7;
 inline constexpr UINT UpdateCheckIntervalMs = 6 * 60 * 60 * 1000;
 struct UpdateResult

tests/input.cpp

@@ -179,6 +179,67 @@ int main(int argc, char **argv) {
                 require(detached.fromNumber==0,"dropping away from badges remains detached");
                 auto translated=ks::dragScreenshotMark(linked[2],ks::MarkPart::Body,{80,35},{85,40},160,100);
                 require(translated.fromNumber==0 && translated.toNumber==0,"moving whole arrow detaches both endpoints");
+                for(auto shape : {ks::ScreenshotShape::Rectangle,ks::ScreenshotShape::Circle,ks::ScreenshotShape::Ellipse}) {
+                    std::vector<ks::ScreenshotMark> objects={{{100,50},{160,110},0},{{10,80},{100,80},0},{{10,140},{55,80},0}};
+                    objects[0].shape=shape;
+                    ks::linkScreenshotEndpoint(objects[1],false,{100,80},objects,6);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[1].toLink.target==objects[0].id && objects[1].to.x==100,"arrow attaches to shape boundary");
+                    ks::linkScreenshotEndpoint(objects[2],false,{55,80},objects,6);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[2].toLink.target==objects[1].id,"arrow attaches to another arrow body");
+                    auto targetId=objects[0].id,arrowId=objects[1].id;
+                    auto snapshot=objects; ks::ScreenshotHistory linksHistory; linksHistory.remember(objects);
+                    // Reverse storage order so dependency resolution cannot rely on insertion order.
+                    std::reverse(objects.begin(),objects.end());
+                    objects[2]=ks::dragScreenshotMark(objects[2],ks::MarkPart::Body,{0,0},{20,20},400,300);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[1].to.x==120 && objects[1].to.y==100 && objects[0].to.x==65 && objects[0].to.y==90,
+                            "shape-arrow-arrow chain updates in dependency order");
+                    require(linksHistory.undo(objects) && objects[1].to.x==100 && objects[2].toLink.target==arrowId,
+                            "undo restores geometry and generic links");
+                    require(linksHistory.redo(objects) && objects[0].to.x==65,"redo restores moved chain");
+                    auto resized=objects;
+                    auto corner=resized[2].to;
+                    resized[2]=ks::dragScreenshotMark(resized[2],ks::MarkPart::End,corner,{corner.x+20,corner.y+20},400,300);
+                    ks::resolveScreenshotLinks(resized);
+                    require(resized[1].to.x==120 && resized[1].to.y==110 && resized[0].to.y==95,
+                            "resizing shapes updates both levels of attached arrows");
+                    ks::linkScreenshotEndpoint(objects[1],true,objects[0].from,objects,6);
+                    require(!objects[1].fromLink.target,"cyclic arrow links are rejected");
+                    auto clone=ks::cloneScreenshotMark(objects[1],objects,400,300);
+                    require(!clone.id && !clone.fromLink.target && !clone.toLink.target,"cloned connector has independent identity and no links");
+                    auto endpoint=objects[1].to;
+                    objects.erase(objects.begin()+2); ks::resolveScreenshotLinks(objects);
+                    require(!objects[1].toLink.target && objects[1].to.x==endpoint.x && objects[0].toLink.target==arrowId,
+                            "deleting shape detaches only its dependents without moving endpoints");
+                    objects.push_back(snapshot[0]); objects.back().id=0; ks::resolveScreenshotLinks(objects);
+                    require(objects.back().id!=targetId && !objects[1].toLink.target,"new objects cannot revive deleted links");
+                }
+                {
+                    std::vector<ks::ScreenshotMark> objects={{{80,40},{80,40},0},{{10,40},{80,40},0}};
+                    objects[0].text=L"Target"; objects[0].fontSize=20;
+                    auto bounds=ks::screenshotTextBounds(objects[0]);
+                    ks::linkScreenshotEndpoint(objects[1],false,{bounds.left,(bounds.top+bounds.bottom)/2},objects,6);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[1].toLink.target==objects[0].id,"arrow attaches to text block");
+                    auto old=objects[1].to;
+                    objects[0]=ks::dragScreenshotMark(objects[0],ks::MarkPart::Body,{0,0},{30,20},400,300);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[1].to.x==old.x+30 && objects[1].to.y==old.y+20,"text attachment follows movement");
+                    objects[0].rotation=90; ks::resolveScreenshotLinks(objects);
+                    require(objects[1].to.x!=old.x+30 || objects[1].to.y!=old.y+20,"text attachment follows rotation");
+                }
+                for(bool freehand : {false,true}) {
+                    std::vector<ks::ScreenshotMark> objects={{{80,60},{160,80},0},{{10,140},{110,60},0}};
+                    objects[0].points={{80,60},{140,60},{160,80}}; objects[0].freehand=freehand;
+                    ks::linkScreenshotEndpoint(objects[1],false,{110,60},objects,6);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[1].toLink.target==objects[0].id,"arrow attaches to freehand and highlight strokes");
+                    objects[0]=ks::dragScreenshotMark(objects[0],ks::MarkPart::Body,{0,0},{20,20},400,300);
+                    ks::resolveScreenshotLinks(objects);
+                    require(objects[1].to.x==130 && objects[1].to.y==80,"stroke attachment follows the original segment");
+                }
                 auto lastPoint=linked[2].from;
                 linked.erase(linked.begin());
                 ks::resolveScreenshotLinks(linked);

tests/screenshot_ui.cpp

@@ -94,6 +94,56 @@ int main()
         c.hoveredPart=ks::MarkPart::Rotation; ks::updateStatus(c);
         require(c.statusText.find(L"15-degree")!=std::wstring::npos,"rotation hint explains Shift snapping");
         c.hoveredPart=ks::MarkPart::None;
+        // Drag the two badges in turn, including a click near the attached endpoint.
+        for(bool freehand : {false,true}) for(auto ends : {ks::LineEnds::End,ks::LineEnds::None}) {
+            c.marks={{{60,80},{60,80},1},{{230,80},{230,80},2},{{60,80},{230,80},0}};
+            auto &connector=c.marks[2]; connector.fromNumber=1; connector.toNumber=2;
+            connector.ends=ends; connector.freehand=freehand;
+            if(freehand) connector.points={{60,80},{140,80},{230,80}};
+            ks::resolveScreenshotLinks(c.marks); c.selected=-1; c.selectedLabel=false;
+            auto mouse=[&](UINT message,POINT p) {
+                LONG x=c.view.left+MulDiv(p.x,c.view.right-c.view.left,c.image->width);
+                LONG y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
+                SendMessageW(window,message,message==WM_LBUTTONUP?0:MK_LBUTTON,MAKELPARAM(x,y));
+            };
+            for(int badge : {0,1,0,1}) {
+                auto origin=c.marks[badge].from;
+                // The second badge's inner edge overlaps the connector endpoint hit area.
+                if(badge==1) origin.x-=12;
+                mouse(WM_LBUTTONDOWN,origin);
+                require(c.selected==badge && c.part==ks::MarkPart::Body,"click on linked badge selects badge instead of connector endpoint");
+                mouse(WM_MOUSEMOVE,{origin.x,origin.y+20});
+                mouse(WM_LBUTTONUP,{origin.x,origin.y+20});
+                require(c.marks[2].fromNumber==1 && c.marks[2].toNumber==2,"alternating badge drags preserve both connector links");
+                auto start=c.marks[0].from,end=c.marks[1].from;
+                require(std::abs(std::hypot(double(c.marks[2].from.x-start.x),double(c.marks[2].from.y-start.y))-15)<1 &&
+                        std::abs(std::hypot(double(c.marks[2].to.x-end.x),double(c.marks[2].to.y-end.y))-15)<1,
+                        "connector endpoints follow both badge rims");
+            }
+            // Selecting a linked connector (also the first click of a double-click)
+            // must not detach it before opening its caption editor.
+            for(int entry : {0,1,2}) {
+                c.selected=-1;
+                POINT body{110,c.marks[0].from.y};
+                if(freehand) body={(c.marks[2].points[0].x+c.marks[2].points[1].x)/2,
+                                   (c.marks[2].points[0].y+c.marks[2].points[1].y)/2};
+                mouse(WM_LBUTTONDOWN,body); mouse(WM_LBUTTONUP,body);
+                require(c.selected==2 && c.marks[2].fromNumber==1 && c.marks[2].toNumber==2,
+                        "clicking a connector without moving preserves both links");
+                if(entry==0) { mouse(WM_LBUTTONDBLCLK,body); mouse(WM_LBUTTONUP,body); }
+                else if(entry==1) SendMessageW(window,WM_KEYDOWN,VK_F2,0);
+                else SendMessageW(window,WM_COMMAND,35,0);
+                require(c.inlineText && c.editingLabel,"linked connector caption opens through every entry point");
+                SendMessageW(c.inlineText,EM_REPLACESEL,TRUE,(LPARAM)L"Linked caption");
+                ks::finishInlineText(window,c,true);
+                require(c.marks[2].label==L"Linked caption" && c.marks[2].fromNumber==1 && c.marks[2].toNumber==2,
+                        "adding or editing a caption preserves both connector links");
+            }
+            c.selected=2;
+            require(ks::markAt(c,c.marks[1].from).first==1,"selected connector cannot steal a badge click");
+            auto outside=c.marks[2].to; outside.x-=4;
+            require(ks::markAt(c,outside)==std::pair{2,ks::MarkPart::End},"endpoint remains draggable outside badge");
+        }
         std::vector<ks::Mark> nudgeMarks;
         nudgeMarks.push_back({{60,60},{60,60},1});
         nudgeMarks.push_back({{60,60},{120,100},0});