fix(api): delete_candidate and delete_candidate_on_current_page (#900)

Previously, the two APIs will always delete the currently selected
candidate, regardless of what its argument is.

src/rime/common.h

@@ -14,9 +14,9 @@
 #include <list>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
-#include <utility>
 #include <unordered_map>
 #include <unordered_set>
 #include <utility>

src/rime/context.cc

@@ -143,27 +143,27 @@ bool Context::Highlight(size_t index) {
   return true;
 }
 
-bool Context::DeleteCandidate(
-    function<an<Candidate>(Segment& seg)> get_candidate) {
+bool Context::DeleteCandidate(std::optional<size_t> index) {
   if (composition_.empty())
     return false;
   Segment& seg(composition_.back());
-  if (auto cand = get_candidate(seg)) {
-    DLOG(INFO) << "Deleting candidate: '" << cand->text();
-    delete_notifier_(this);
-    return true;  // CAVEAT: this doesn't mean anything is deleted for sure
+  auto cand = index ? seg.GetCandidateAt(*index) : seg.GetSelectedCandidate();
+  if (!cand)
+    return false;
+  DLOG(INFO) << "Deleting candidate: " << cand->text();
+  if (index) {
+    seg.selected_index = *index;
   }
-  return false;
+  delete_notifier_(this);
+  return true;  // CAVEAT: this doesn't mean anything is deleted for sure
 }
 
 bool Context::DeleteCandidate(size_t index) {
-  return DeleteCandidate(
-      [index](Segment& seg) { return seg.GetCandidateAt(index); });
+  return DeleteCandidate(std::optional{index});
 }
 
 bool Context::DeleteCurrentSelection() {
-  return DeleteCandidate(
-      [](Segment& seg) { return seg.GetSelectedCandidate(); });
+  return DeleteCandidate({});
 }
 
 bool Context::ConfirmCurrentSelection() {

src/rime/context.h

@@ -94,7 +94,7 @@ class RIME_API Context {
 
  private:
   string GetSoftCursor() const;
-  bool DeleteCandidate(function<an<Candidate>(Segment& seg)> get_candidate);
+  bool DeleteCandidate(std::optional<size_t> index);
 
   string input_;
   size_t caret_pos_ = 0;

tools/rime_api_console.cc

@@ -165,6 +165,26 @@ bool execute_special_command(const char* line, RimeSessionId session_id) {
   if (!strcmp(line, "synchronize")) {
     return rime->sync_user_data();
   }
+  const char* kDeleteCandidateOnCurrentPage = "delete on current page ";
+  command_length = strlen(kDeleteCandidateOnCurrentPage);
+  if (!strncmp(line, kDeleteCandidateOnCurrentPage, command_length)) {
+    const char* index_str = line + command_length;
+    int index = atoi(index_str);
+    if (!rime->delete_candidate_on_current_page(session_id, index)) {
+      fprintf(stderr, "failed to delete\n");
+    }
+    return true;
+  }
+  const char* kDeleteCandidate = "delete ";
+  command_length = strlen(kDeleteCandidate);
+  if (!strncmp(line, kDeleteCandidate, command_length)) {
+    const char* index_str = line + command_length;
+    int index = atoi(index_str);
+    if (!rime->delete_candidate(session_id, index)) {
+      fprintf(stderr, "failed to delete\n");
+    }
+    return true;
+  }
   return false;
 }