MIT App Inventor Conditional Logic and Screen Navigation - كتاب هندسة البرمجيات - الصف 12 - الفصل 1 - المملكة العربية السعودية

وزارة التعليم Ministry of Education 171 2025 - 1447 --- VISUAL CONTEXT --- **DIAGRAM**: MIT App Inventor Blocks Editor - Control Blocks Description: A screenshot of the MIT App Inventor development environment. The top bar shows 'Projects', 'Connect', 'Build'. The screen name is 'Visit_SA_App', and the current component is 'AlMasmak'. Options to 'Add Screen' and 'Remove' are visible. The left panel, labeled 'Blocks', shows 'Built-in' categories. 'Control' is checked, indicating its blocks are displayed. The categories listed are: 'Control', 'Logic', 'Math', 'Text', 'Lists', 'Dictionaries', 'Colors', 'Variables', 'Procedures'. The right panel, labeled 'Viewer', displays two identical 'if then else' blocks, ready for use in programming logic. Key Values: MIT APP INVENTOR, Projects, Connect, Build, Visit_SA_App, AlMasmak, Add Screen, Remove, Blocks, Viewer, Built-in, Control, Logic, Math, Text, Lists, Dictionaries, Colors, Variables, Procedures, if, then, else Context: Illustrates the initial state of the App Inventor Blocks editor and the availability of control flow blocks like 'if then else'. **DIAGRAM**: Adding 'else if' to a Conditional Block Description: A programming block structure starting with 'when AlMasmak .Initialize do'. This event block contains an 'if then else' block. A dashed blue arrow, labeled with the number '4', points from the 'else' part of the 'if then else' block to a magnified inset. This inset shows a pop-up menu with options to add 'else if' or 'else' clauses to the conditional block, typically accessed via a gear icon on the 'if' block. The 'else if' option is highlighted. Key Values: when AlMasmak .Initialize, do, if, then, else, else if Context: Demonstrates how to modify an 'if' block to include multiple conditional branches using 'else if' clauses in App Inventor. **DIAGRAM**: MIT App Inventor Blocks Editor - Logic Blocks Description: A screenshot of the MIT App Inventor development environment. The top bar shows 'Projects', 'Connect', 'Build'. The screen name is 'Visit_SA_App', and the current component is 'AlMasmak'. Options to 'Add Screen' and 'Remove' are visible. The left panel, labeled 'Blocks', shows 'Built-in' categories. 'Logic' is checked, indicating its blocks are displayed. The categories listed are: 'Control', 'Logic', 'Math', 'Text', 'Lists', 'Dictionaries', 'Colors', 'Variables', 'Procedures'. The right panel, labeled 'Viewer', displays several logic blocks: 'true', 'false', 'not', and '=' (equality comparison). Key Values: MIT APP INVENTOR, Projects, Connect, Build, Visit_SA_App, AlMasmak, Add Screen, Remove, Blocks, Viewer, Built-in, Control, Logic, Math, Text, Lists, Dictionaries, Colors, Variables, Procedures, true, false, not, = Context: Shows the available logic blocks in App Inventor, which are essential for constructing conditions in 'if' statements. **DIAGRAM**: Integrating Logic Blocks into Conditional Statements Description: A programming block structure starting with 'when AlMasmak .Initialize do'. This event block contains an 'if then else if then' block, indicating multiple conditional branches. The conditions for both the 'if' and 'else if' clauses are filled with '=' (equality) logic blocks, ready to compare values. A dashed blue arrow, labeled with the number '5', connects this diagram to the 'Logic' blocks shown in the middle-left diagram, indicating the source of the '=' block. Key Values: when AlMasmak .Initialize, do, if, then, else if, then, = Context: Illustrates how to integrate logic comparison blocks into the conditional slots of 'if/else if' statements to define specific conditions. **DIAGRAM**: Screen Navigation and Value Passing Blocks Description: A screenshot of the App Inventor 'Viewer' area displaying various programming blocks related to control flow and screen operations. These include: 'then', 'else', 'do', 'result', 'evaluate but ignore result', 'open another screen screenName AlMasmak', 'open another screen with start value screenName AlMasmak startValue', and 'get start value'. A blue circle with the number '6' highlights the 'get start value' block. Key Values: Viewer, then, else, do, result, evaluate but ignore result, open another screen screenName, AlMasmak, open another screen with start value screenName, startValue, get start value Context: Shows blocks used for navigating between screens, passing data to new screens, and retrieving data passed to the current screen. **DIAGRAM**: Using 'get start value' in Conditional Logic Description: A programming block structure starting with 'when AlMasmak .Initialize do'. This event block contains an 'if then else if then' block. The conditions for both the 'if' and 'else if' clauses are filled with 'get start value =' blocks, indicating a comparison involving a value passed to the screen upon initialization. A dashed blue arrow, originating from the 'get start value' block in the bottom-left diagram and labeled with the number '6', points to this diagram, showing its application. Key Values: when AlMasmak .Initialize, do, if, then, else if, then, get start value, = Context: Demonstrates how to use the 'get start value' block within conditional statements to execute different logic paths based on data received when the screen starts.