Mouse cursor movements

1 files changed, 77 insertions, 2 deletions

diff --git a/src/ui_elements/TextEditor.c b/src/ui_elements/TextEditor.c
index e114080..13401d8 100644
--- a/src/ui_elements/TextEditor.c
+++ b/src/ui_elements/TextEditor.c
@@ -5,6 +5,7 @@
 #include "../resources/resources.h"
 #include <ctype.h>
 #include <raylib.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -22,6 +23,30 @@ float GetCursorXPos(TextArea *ta) {
     return x_position;
 }
 
+// Returns the position the cursor should be in on the given offset. 
+size_t GetCharIdxByOffset(TextArea *ta, int line, float offset) {
+    if (ta == NULL) return 0;
+    TextNode *node = ta->StartNode;
+    for (int i = 0; i < line; i++) {
+        node = node->NextNode;
+        if (node == NULL) return 0;
+    }
+
+    for (int i = 0; i < node->len; i++) {
+        char original_char = node->text[i + 1];
+        node->text[i + 1] = '\0'; 
+        
+        float width = MeasureTextEx(*ta->DisplayParams->font,
+                node->text,
+                ta->DisplayParams->font_size, 
+                ta->DisplayParams->spacing).x;
+
+        node->text[i + 1] = original_char;
+        if (width > offset) return i;
+    }
+    return node->len;
+}
+
 /// We pass x_position not to call GetCursorXPos twice (it's expencive)
 void DrawCursor(TextArea *ta, Vector2 lineStartPos, float x_position) {
     DrawLine(lineStartPos.x + x_position, lineStartPos.y, 
@@ -284,6 +309,31 @@ void MoveCursorHome(TextArea *ta) {
     ta->CursorPosition.x = 0;
 }
 
+// Moves cursor to the position
+void MoveCursorTo(TextArea *ta, int x, int y)  {
+    // Making sure we are in bounds
+    if (y >= ta->NodeLenth) y = ta->NodeLenth - 1;
+    if (y < 0) y = 0;
+    if (x < 0) x = 0;
+
+    if (ta->CursorPosition.y < y) {
+        int diff = y - ta->CursorPosition.y;
+        for (int i = 0; i < diff; i++) {
+            ta->CurrentNode = ta->CurrentNode->NextNode;
+        }
+    } else if (ta->CursorPosition.y > y) {
+        int diff = ta->CursorPosition.y - y;
+        for (int i = 0; i < diff; i++) {
+            ta->CurrentNode = ta->CurrentNode->PrevNode;
+        }
+    }
+
+    ta->CursorPosition.y = y;
+    // We could't make sure that was the case before
+    if (x > ta->CurrentNode->len) x = ta->CurrentNode->len;
+    ta->CursorPosition.x = x;
+}
+
 size_t GetStartingSpaces(char *string) {
     if (string == NULL) return 0;
     size_t idx = 0, len = strlen(string);
@@ -479,6 +529,16 @@ void PrintAllLines(TextArea *ta) {
     }
 }
 
+/// Returns the position on the text field excluding onscreen offset and scroll
+Vector2 absolutePosToTextPos(TextArea *ta, Rectangle *rec, Vector2 pos) {
+    if (ta == NULL || ta->DisplayParams == NULL || rec == NULL) 
+        return (Vector2){0, 0};
+    return (Vector2) {
+        .x = pos.x - rec->x + ta->DisplayParams->scroll_h,
+        .y = pos.y - rec->y + ta->DisplayParams->scroll_v,
+    };
+}
+
 /// Assumes that control is pressed
 void HandleControlComands(TextArea *ta) {
     if (IsKeyPressedFix(KEY_RIGHT)) MoveCursorRightWord(ta);
@@ -563,19 +623,34 @@ void HandleScroll(TextArea *ta, Rectangle rec) {
         // lazy eval caching
     } else {
         int text_height = ta->NodeLenth * ta->DisplayParams->font_size;
-        int max_scroll = text_height - rec.height;
+        int max_scroll = text_height - ta->DisplayParams->font_size * 2;
         ta->DisplayParams->scroll_v -= scroll;
         if (ta->DisplayParams->scroll_v < 0)
             ta->DisplayParams->scroll_v = 0;
-        if (text_height > rec.height && ta->DisplayParams->scroll_v > max_scroll)
+        if (max_scroll > 0 && ta->DisplayParams->scroll_v > max_scroll)
             ta->DisplayParams->scroll_v = max_scroll;
     }
 }
 
+void HandleMouseEvents(TextArea *ta, Rectangle *rec) {
+    if (IsMouseButtonPressed(MOUSE_BUTTON_LEFT)) {
+        Vector2 mousePos = GetMousePosition();
+        Vector2 onTextPos = absolutePosToTextPos(ta, rec, mousePos);
+        int cursorLine = (int)(onTextPos.y / ta->DisplayParams->font_size);
+        size_t cursorChar = GetCharIdxByOffset(ta, cursorLine, onTextPos.x);
+        // TraceLog(LOG_INFO, "Mouse pos:    { %d; %d }", (int)mousePos.x, (int)mousePos.y);
+        // TraceLog(LOG_INFO, "OnScreen pos: { %d; %d }", (int)onTextPos.x, (int)onTextPos.y);
+        // TraceLog(LOG_INFO, "Line:         %d", cursorLine);
+        // TraceLog(LOG_INFO, "Char:         %zu", cursorChar);
+        MoveCursorTo(ta, cursorChar, cursorLine);
+    }
+}
+
 void UpdateTextArea(TextArea *ta, Rectangle rec) {
     HandleKeyboard(ta);
     if (IsMouseInRec(rec)) {
         HandleScroll(ta, rec);
+        HandleMouseEvents(ta, &rec);
     }
 }