KERNEL-13232 feat: 复选树的连接线之类的不再用图片了

src/less/base/tree/ztree.less

@@ -190,6 +190,56 @@
   }
 }
 
+.ztree.solid li span.button.roots_docu {
+  background: none;
+  position: relative;
+
+  &:before {
+    position: absolute;
+    bottom: 0;
+    left: -1px;
+    width: 50%;
+    height: 50%;
+    border-right: 1px solid @border-color-dark-gray-line;
+    content: '';
+  }
+
+  &:after {
+    position: absolute;
+    top: 0;
+    right: 0;
+    height: 50%;
+    width: 50%;
+    border-bottom: 1px solid @border-color-dark-gray-line;
+    content: '';
+  }
+}
+
+.ztree.solid li span.button.center_docu {
+  background: none;
+  position: relative;
+
+  &:before {
+    position: absolute;
+    top: 0;
+    left: -1px;
+    width: 50%;
+    height: 100%;
+    border-right: 1px solid @border-color-dark-gray-line;
+    content: '';
+  }
+
+  &:after {
+    position: absolute;
+    top: 0;
+    right: 0;
+    height: 50%;
+    width: 50%;
+    border-bottom: 1px solid @border-color-dark-gray-line;
+    content: '';
+  }
+}
+
 .ztree.solid li span.button.bottom_docu {
   background: none;
   position: relative;
@@ -215,6 +265,19 @@
   }
 }
 
+.bi-theme-dark {
+  .ztree.solid li span.button.center_docu, .ztree.solid li span.button.bottom_docu {
+    &:before {
+      border-right: 1px solid @border-color-dark-gray-line-theme-dark;
+    }
+
+    &:after {
+      border-bottom: 1px solid @border-color-dark-gray-line-theme-dark;
+    }
+  }
+}
+
+
 .ztree li span.button.chk {
   position: relative;
   .use-scale(width, 14px);

src/less/case/tree/tree.item.less

@@ -1,6 +1,29 @@
 @import "../../index.less";
 
-.tree-first-solid-line-conn-background, .tree-mid-solid-line-conn-background {
+.tree-first-solid-line-conn-background {
+  &:before {
+    position: absolute;
+    bottom: 0;
+    left: -1px;
+    width: 50%;
+    height: 50%;
+    border-right: 1px solid @border-color-dark-gray-line;
+    content: '';
+  }
+
+  &:after {
+    position: absolute;
+    top: 0;
+    right: 0;
+    height: 50%;
+    width: 50%;
+    border-bottom: 1px solid @border-color-dark-gray-line;
+    content: '';
+  }
+}
+
+
+.tree-mid-solid-line-conn-background {
   &:before {
     position: absolute;
     top: 0;

src/less/resource/background.less

@@ -179,36 +179,20 @@
   .image2xPath(@icon-tree-vertical-line-2);
 }
 
-.ztree.solid li span.button.roots_docu {
-  .image2xPath(@icon-tree-solid-vertical-line-2);
-}
-
 .bi-theme-dark {
   .ztree li span.button.roots_docu {
     .image2xPath(@icon-tree-vertical-line-2-theme-dark);
   }
-
-  .ztree.solid li span.button.roots_docu {
-    .image2xPath(@icon-tree-solid-vertical-line-2-theme-dark);
-  }
 }
 
 .ztree li span.button.center_docu {
   .image2xPath(@icon-tree-vertical-line-3);
 }
 
-.ztree.solid li span.button.center_docu {
-  .image2xPath(@icon-tree-solid-vertical-line-3);
-}
-
 .bi-theme-dark {
   .ztree li span.button.center_docu {
     .image2xPath(@icon-tree-vertical-line-3-theme-dark);
   }
-
-  .ztree.solid li span.button.center_docu {
-    .image2xPath(@icon-tree-solid-vertical-line-3-theme-dark);
-  }
 }
 
 .ztree li span.button.bottom_docu {
@@ -220,10 +204,6 @@
   .ztree li span.button.bottom_docu {
     .image2xPath(@icon-tree-vertical-line-4-theme-dark);
   }
-
-  .ztree.solid li span.button.bottom_docu {
-    .image2xPath(@icon-tree-solid-vertical-line-4-theme-dark);
-  }
 }
 
 .ztree li span.button.ico_loading {