Selecting text with mouse

src/main/kotlin/ru/dbotthepony/mc/otm/client/screen/panels/TextInputPanel.kt

@@ -515,6 +515,64 @@ open class TextInputPanel<out S : Screen>(
 			if (result.couldHaveChangedLine) Int.MAX_VALUE else result.newCharacter))
 	}
 
+	private fun simulateSelectionUp(): Boolean {
+		if (cursorLine <= 0)
+			return false
+
+		val cursorCharacter = cursorCharacter
+		val cursorLine = cursorLine
+
+		while (this.cursorCharacter >= 0 && this.cursorLine == cursorLine) {
+			simulateSelectLeft(false)
+		}
+
+		val line = this[this.cursorLine]!!
+
+		if (cursorCharacter < line.length) {
+			this.cursorCharacter = line.length
+
+			while (this.cursorCharacter > cursorCharacter) {
+				simulateSelectLeft(false)
+			}
+		}
+
+		this.cursorCharacter = cursorCharacter
+		return true
+	}
+
+	private fun simulateSelectionDown(): Boolean {
+		if (cursorLine >= lines.size - 1)
+			return false
+
+		val cursorCharacter = cursorCharacter
+		val cursorLine = cursorLine
+
+		while (this.cursorCharacter >= cursorCharacter && this.cursorLine == cursorLine) {
+			simulateSelectRight(true)
+		}
+
+		val line = this[this.cursorLine]!!
+
+		if (cursorCharacter < line.length) {
+			this.cursorCharacter = 0
+
+			while (this.cursorCharacter < cursorCharacter) {
+				simulateSelectRight(false)
+			}
+		} else {
+			val store = this.cursorLine
+
+			for (i in 0 .. line.length) {
+				simulateSelectRight(false)
+			}
+
+			this.cursorLine = store
+		}
+
+		this.cursorCharacter = cursorCharacter
+		return true
+	}
+
 	override fun keyPressedInternal(key: Int, scancode: Int, mods: Int): Boolean {
 		if (key == InputConstants.KEY_ESCAPE) {
 			killFocus()
@@ -598,26 +656,7 @@ open class TextInputPanel<out S : Screen>(
 			return true
 		} else if (key == InputConstants.KEY_UP) {
 			if (minecraft.window.isShiftDown) {
-				if (cursorLine > 0) {
-					val cursorCharacter = cursorCharacter
-					val cursorLine = cursorLine
-
-					while (this.cursorCharacter >= 0 && this.cursorLine == cursorLine) {
-						simulateSelectLeft(false)
-					}
-
-					val line = this[this.cursorLine]!!
-
-					if (cursorCharacter < line.length) {
-						this.cursorCharacter = line.length
-
-						while (this.cursorCharacter > cursorCharacter) {
-							simulateSelectLeft(false)
-						}
-					}
-
-					this.cursorCharacter = cursorCharacter
-				}
+				simulateSelectionUp()
 			} else {
 				if (cursorLine > 0) {
 					cursorLine--
@@ -629,34 +668,7 @@ open class TextInputPanel<out S : Screen>(
 			return true
 		} else if (key == InputConstants.KEY_DOWN) {
 			if (minecraft.window.isShiftDown) {
-				if (cursorLine < lines.size - 1) {
-					val cursorCharacter = cursorCharacter
-					val cursorLine = cursorLine
-
-					while (this.cursorCharacter >= cursorCharacter && this.cursorLine == cursorLine) {
-						simulateSelectRight(true)
-					}
-
-					val line = this[this.cursorLine]!!
-
-					if (cursorCharacter < line.length) {
-						this.cursorCharacter = 0
-
-						while (this.cursorCharacter < cursorCharacter) {
-							simulateSelectRight(false)
-						}
-					} else {
-						val store = this.cursorLine
-
-						for (i in 0 .. line.length) {
-							simulateSelectRight(false)
-						}
-
-						this.cursorLine = store
-					}
-
-					this.cursorCharacter = cursorCharacter
-				}
+				simulateSelectionDown()
 			} else {
 				if (cursorLine < lines.size - 1) {
 					cursorLine++
@@ -930,14 +942,21 @@ open class TextInputPanel<out S : Screen>(
 		BUFFER.endBatch()
 	}
 
+	var isSelecting = false
+		protected set
+
 	override fun mouseClickedInner(x: Double, y: Double, button: Int): Boolean {
 		selections.clear()
 		requestFocus()
 
-		val (lx, ly) = screenToLocal(x, y)
-		val pos = localToText(lx, ly)
-		cursorLine = pos.y
-		cursorCharacter = pos.x
+		if (button == InputConstants.MOUSE_BUTTON_LEFT) {
+			val (lx, ly) = screenToLocal(x, y)
+			val pos = localToText(lx, ly)
+			cursorLine = pos.y
+			cursorCharacter = pos.x
+
+			isSelecting = true
+		}
 
 		return true
 	}
@@ -996,6 +1015,40 @@ open class TextInputPanel<out S : Screen>(
 		return Vector2i(sLine.length, line)
 	}
 
+	override fun mouseReleasedInner(x: Double, y: Double, button: Int): Boolean {
+		if (button == InputConstants.MOUSE_BUTTON_LEFT)
+			isSelecting = false
+
+		return true
+	}
+
+	override fun mouseDraggedInner(x: Double, y: Double, button: Int, xDelta: Double, yDelta: Double): Boolean {
+		if (button != InputConstants.MOUSE_BUTTON_LEFT || !isSelecting)
+			return true
+
+		val (lx, ly) = screenToLocal(x, y)
+		val pos = localToText(lx, ly)
+		val cursorLine = pos.y
+		val cursorCharacter = pos.x
+
+		while (cursorLine > this.cursorLine && simulateSelectionDown()) {}
+		while (cursorLine < this.cursorLine && simulateSelectionUp()) {}
+
+		var lastCursorCharacter = this.cursorCharacter + 1
+
+		while (cursorCharacter < this.cursorCharacter && lastCursorCharacter != this.cursorCharacter) {
+			lastCursorCharacter = this.cursorCharacter
+			simulateSelectLeft(false)
+		}
+
+		while (cursorCharacter > this.cursorCharacter && lastCursorCharacter != this.cursorCharacter) {
+			lastCursorCharacter = this.cursorCharacter
+			simulateSelectRight(false)
+		}
+
+		return true
+	}
+
 	private enum class CharType {
 		SPACES {
 			override fun contains(input: Char): Boolean {